diff --git a/android-app-core/res/values/preferences.xml b/android-app-core/res/values/preferences.xml
deleted file mode 100644
index fbfec9ae..00000000
--- a/android-app-core/res/values/preferences.xml
+++ /dev/null
@@ -1,27 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-  ~ Copyright 2013 serso aka se.solovyev
-  ~
-  ~ Licensed under the Apache License, Version 2.0 (the "License");
-  ~ you may not use this file except in compliance with the License.
-  ~ You may obtain a copy of the License at
-  ~
-  ~    http://www.apache.org/licenses/LICENSE-2.0
-  ~
-  ~ Unless required by applicable law or agreed to in writing, software
-  ~ distributed under the License is distributed on an "AS IS" BASIS,
-  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
-  ~ limitations under the License.
-  ~
-  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-  ~ Contact details
-  ~
-  ~ Email: se.solovyev@gmail.com
-  ~ Site:  http://se.solovyev.org
-  -->
-
-<resources>
-	<string name="p_calc_functions">org.solovyev.android.calculator.CalculatorModel_functions</string>
-	<string name="p_calc_vars">org.solovyev.android.calculator.CalculatorModel_vars</string>
-</resources>
\ No newline at end of file
diff --git a/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidCalculatorEngine.java b/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidCalculatorEngine.java
index 7863c5a5..995ced40 100644
--- a/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidCalculatorEngine.java
+++ b/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidCalculatorEngine.java
@@ -128,8 +128,8 @@ public class AndroidCalculatorEngine implements CalculatorEngine, SharedPreferen
 
 		final JsclMathEngine engine = JsclMathEngine.getInstance();
 		this.calculatorEngine = new CalculatorEngineImpl(engine,
-				new CalculatorVarsRegistry(engine.getConstantsRegistry(), new AndroidMathEntityDao<Var>(R.string.p_calc_vars, application, Vars.class)),
-				new CalculatorFunctionsMathRegistry(engine.getFunctionsRegistry(), new AndroidMathEntityDao<AFunction>(R.string.p_calc_functions, application, Functions.class)),
+				new CalculatorVarsRegistry(engine.getConstantsRegistry(), new AndroidMathEntityDao<Var>("org.solovyev.android.calculator.CalculatorModel_vars", application, Vars.class)),
+				new CalculatorFunctionsMathRegistry(engine.getFunctionsRegistry(), new AndroidMathEntityDao<AFunction>("org.solovyev.android.calculator.CalculatorModel_functions", application, Functions.class)),
 				new CalculatorOperatorsMathRegistry(engine.getOperatorsRegistry(), new AndroidMathEntityDao<MathPersistenceEntity>(null, application, null)),
 				new CalculatorPostfixFunctionsRegistry(engine.getPostfixFunctionsRegistry(), new AndroidMathEntityDao<MathPersistenceEntity>(null, application, null)),
 				this.lock);
diff --git a/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidMathEntityDao.java b/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidMathEntityDao.java
index 8379f076..3cad19e7 100644
--- a/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidMathEntityDao.java
+++ b/android-app-core/src/main/java/org/solovyev/android/calculator/model/AndroidMathEntityDao.java
@@ -51,7 +51,7 @@ public class AndroidMathEntityDao<T extends MathPersistenceEntity> implements Ma
 	private static final String TAG = AndroidMathEntityDao.class.getSimpleName();
 
 	@Nullable
-	private final Integer preferenceStringId;
+	private final String preferenceString;
 
 	@Nonnull
 	private final Context context;
@@ -59,17 +59,17 @@ public class AndroidMathEntityDao<T extends MathPersistenceEntity> implements Ma
 	@Nullable
 	private final Class<? extends MathEntityPersistenceContainer<T>> persistenceContainerClass;
 
-	public AndroidMathEntityDao(@Nullable Integer preferenceStringId,
+	public AndroidMathEntityDao(@Nullable String preferenceString,
 								@Nonnull Application application,
 								@Nullable Class<? extends MathEntityPersistenceContainer<T>> persistenceContainerClass) {
-		this.preferenceStringId = preferenceStringId;
+		this.preferenceString = preferenceString;
 		this.context = application;
 		this.persistenceContainerClass = persistenceContainerClass;
 	}
 
 	@Override
 	public void save(@Nonnull MathEntityPersistenceContainer<T> container) {
-		if (preferenceStringId != null) {
+		if (preferenceString != null) {
 			final SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
 			final SharedPreferences.Editor editor = settings.edit();
 
@@ -81,7 +81,7 @@ public class AndroidMathEntityDao<T extends MathPersistenceEntity> implements Ma
 				throw new RuntimeException(e);
 			}
 
-			editor.putString(context.getString(preferenceStringId), sw.toString());
+			editor.putString(preferenceString, sw.toString());
 
 			editor.commit();
 		}
@@ -90,11 +90,11 @@ public class AndroidMathEntityDao<T extends MathPersistenceEntity> implements Ma
 	@Nullable
 	@Override
 	public MathEntityPersistenceContainer<T> load() {
-		if (persistenceContainerClass != null && preferenceStringId != null) {
+		if (persistenceContainerClass != null && preferenceString != null) {
 			final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
 
 			if (preferences != null) {
-				final String value = preferences.getString(context.getString(preferenceStringId), null);
+				final String value = preferences.getString(preferenceString, null);
 				if (value != null) {
 					final Serializer serializer = new Persister();
 					try {
diff --git a/android-app/res/values-large/arrays.xml b/android-app/res/values-large/arrays.xml
index c6bcbbc0..4d508828 100644
--- a/android-app/res/values-large/arrays.xml
+++ b/android-app/res/values-large/arrays.xml
@@ -28,7 +28,7 @@
 		<item>@string/p_layout_simple</item>
 		<item>@string/p_layout_simple_mobile</item>
 	</string-array>
-	<string-array name="p_layout_values">
+	<string-array name="p_layout_values" translatable="false">
 		<item>main_calculator</item>
 		<item>main_calculator_mobile</item>
 		<item>simple</item>
diff --git a/android-app/res/values/arrays.xml b/android-app/res/values/arrays.xml
index 7742c23a..23de9ed4 100644
--- a/android-app/res/values/arrays.xml
+++ b/android-app/res/values/arrays.xml
@@ -29,7 +29,7 @@
 		<item>@string/p_metro_green_theme</item>
 		<item>@string/p_metro_purple_theme</item>
 	</string-array>
-	<string-array name="p_theme_values">
+	<string-array name="p_theme_values" translatable="false">
 		<item>default_theme</item>
 		<item>violet_theme</item>
 		<item>light_blue_theme</item>
@@ -43,13 +43,13 @@
 		<item>@string/p_grouping_separator_apostrophe</item>
 		<item>@string/p_grouping_separator_space</item>
 	</string-array>
-	<string-array name="p_grouping_separator_values">
+	<string-array name="p_grouping_separator_values" translatable="false">
 		<item>""</item>
 		<item>\'</item>
 		<item>" "</item>
 	</string-array>
 
-	<string-array name="p_multiplication_sign_values">
+	<string-array name="p_multiplication_sign_values" translatable="false">
 		<item>"*"</item>
 		<item>"×"</item>
 		<item>"∙"</item>
@@ -59,7 +59,7 @@
 		<item>@string/p_layout_calculator</item>
 		<item>@string/p_layout_simple</item>
 	</string-array>
-	<string-array name="p_layout_values">
+	<string-array name="p_layout_values" translatable="false">
 		<item>main_calculator</item>
 		<item>simple</item>
 	</string-array>
@@ -69,7 +69,7 @@
 		<item>@string/p_calc_haptic_feedback_strength_middle</item>
 		<item>@string/p_calc_haptic_feedback_strength_long</item>
 	</string-array>
-	<string-array name="p_calc_haptic_feedback_duration_values">
+	<string-array name="p_calc_haptic_feedback_duration_values" translatable="false">
 		<item>30</item>
 		<item>60</item>
 		<item>100</item>
@@ -81,7 +81,7 @@
 		<item>@string/p_grad</item>
 		<item>@string/p_turns</item>
 	</string-array>
-	<string-array name="p_angle_units">
+	<string-array name="p_angle_units" translatable="false">
 		<item>deg</item>
 		<item>rad</item>
 		<item>grad</item>
@@ -94,7 +94,7 @@
 		<item>@string/p_oct</item>
 		<item>@string/p_bin</item>
 	</string-array>
-	<string-array name="p_numeral_bases">
+	<string-array name="p_numeral_bases" translatable="false">
 		<item>dec</item>
 		<item>hex</item>
 		<item>oct</item>