diff --git a/cyrtranslit/__init__.py b/cyrtranslit/__init__.py
index 387d0a1..7ccc732 100644
--- a/cyrtranslit/__init__.py
+++ b/cyrtranslit/__init__.py
@@ -135,11 +135,11 @@ def to_cyrillic(string_to_transliterate, lang_code='sr'):
                     (c in u'Šš' and c_plus_1 in u'č')      # šč
                 )) or \
                (lang_code == "mn" and (
-                       (c in u'Kk' and c_plus_1 == u'h') or  # Х х
-                       (c in u'Ss' and c_plus_1 == u'h') or  # Ш ш
-                       (c in u'Tt' and c_plus_1 == u's') or  # Ц ц
-                       (c in u'Cc' and c_plus_1 == u'h') or  # Ч ч
-                       (c in u'Yy' and c_plus_1 in u'eoua')  # Е Ё Ю Я
+                    (c in u'Kk' and c_plus_1 in u'Hh') or  # Х х
+                    (c in u'Ss' and c_plus_1 in u'Hh') or  # Ш ш
+                    (c in u'Tt' and c_plus_1 in u'Ss') or  # Ц ц
+                    (c in u'Cc' and c_plus_1 in u'Hh') or  # Ч ч
+                    (c in u'Yy' and c_plus_1 in u'EeOoUuAa')  # Е Ё Ю Я
                 )):
                 index += 1
                 c += c_plus_1
diff --git a/cyrtranslit/mapping.py b/cyrtranslit/mapping.py
index b814f8b..41d993d 100644
--- a/cyrtranslit/mapping.py
+++ b/cyrtranslit/mapping.py
@@ -303,28 +303,44 @@
     u"Ф", u"F", u"ф", u"f",
     u"К", u"K", u"к", u"k",
     u"Х", u"Kh", u"х", u"kh",        # lat 1
+    u"Х", u"KH", u"х", u"kH",        # lat 1
     u"Г", u"G", u"г", u"g",
     u"С", u"S", u"с", u"s",
     u"Ш", u"Sh", u"ш", u"sh",  # sh  # lat2
+    u"Ш", u"SH", u"ш", u"sH",  # sh  # lat2
     u"Т", u"T", u"т", u"t",
     u"Д", u"D", u"д", u"d",
     u"Ц", u"Ts", u"ц", u"ts",        # lat3
+    u"Ц", u"TS", u"ц", u"tS",        # lat3
     u"Ч", u"Ch", u"ч", u"ch",        # lat4
+    u"Ч", u"CH", u"ч", u"cH",        # lat4
     u"З", u"Z", u"з", u"z",
     u"Ж", u"J", u"ж", u"j",
     u"Й", u"I", u"й", u"i",  # i * 2
     u"Р", u"R", u"р", u"r",
     u"Б", u"B", u"б", u"b",
     u"Е", u"Ye", u"е", u"ye",             # lat 5
+    u"Е", u"YE", u"е", u"yE",             # lat 5
     u"Ё", u"Yo", u"ё", u"yo",             # lat 6
-    u"Щ", u"Sh", u"щ", u"sh",  # sh x 2   # lat 7
+    u"Ё", u"YO", u"ё", u"yO",             # lat 6
+    #u"Щ", u"Sh", u"щ", u"sh",  # sh x 2   # lat 7 # FIXME: How to handle the two possible cyrillic versions of Sh? Ш or Щ?
+    #u"Щ", u"SH", u"щ", u"sH",  # sh x 2   # lat 7 # FIXME: How to handle the two possible cyrillic versions of Sh? Ш or Щ?
     u"Ъ", u"I", u"ъ", u"i",  # i * 3
     u"Ы", u"Y", u"ы", u"y",
     u"Ь", u"I", u"ь", u"i",  # i * 4
     u"Ю", u"Yu", u"ю", u"yu",             # lat 8
+    u"Ю", u"YU", u"ю", u"yU",             # lat 8
     u"Я", u"Ya", u"я", u"ya",             # lat 9
+    u"Я", u"YA", u"я", u"yA",             # lat 9
 ]
-MN_CYR_TO_LAT_DICT = dict([(c, l) for c, l in zip(MN_CYR_LAT_LIST[::2], MN_CYR_LAT_LIST[1::2])])
+# Building the dictionary with the filter to skip pairs with 2-character Latin letters where the second character is uppercase
+MN_CYR_TO_LAT_DICT = {
+    c: l for c, l in zip(MN_CYR_LAT_LIST[::2], MN_CYR_LAT_LIST[1::2])
+    if not (len(l) == 2 and l[1].isupper())
+}
+MN_CYR_TO_LAT_DICT['Щ'] = 'Sh'
+MN_CYR_TO_LAT_DICT['щ'] = 'sh'
+
 MN_LAT_TO_CYR_DICT = dict([(l, c) for c, l in zip(MN_CYR_LAT_LIST[-2::-2], MN_CYR_LAT_LIST[-1::-2])])
 
 # Bundle up all the dictionaries in a lookup dictionary
diff --git a/tests.py b/tests.py
index f992ab1..9353746 100644
--- a/tests.py
+++ b/tests.py
@@ -264,6 +264,26 @@ def test_alphabet_transliteration_latin_to_cyrillic(self):
 
         self.assertEqual(transliterated_mongolian_alphabet, mongolian_alphabet_cyrillic)
 
+    def test_mixed_casing_transliteration_latin_to_cyrillic(self):
+        ''' Transliteration from latin with mixed casing, e.g. Sh SH sh sH.
+        '''
+        input_latin = 'KhKHkhkHShSHshsHTsTStstSChCHchcHYeYEyeyEYoYOyoyOYaYAyayA'
+        expected_output_cyrillic = 'ХХххШШшшЦЦццЧЧччЕЕееЁЁёёЯЯяя'
+
+        actual_output_cyrillic = cyrtranslit.to_cyrillic(input_latin, 'mn')
+
+        self.assertEqual(actual_output_cyrillic, expected_output_cyrillic)
+
+    def test_transliteration_cyrillic_to_sh(self):
+        ''' Transliteration from Ш/Щ and ш/щ should be Sh and sh.
+        '''
+        input_cyrillic= 'ШшЩщ'
+        expected_output_latin = 'ShshShsh'
+
+        actual_output_latin = cyrtranslit.to_latin(input_cyrillic, 'mn')
+
+        self.assertEqual(actual_output_latin, expected_output_latin)
+
 
 if __name__ == '__main__':
     # Run all tests.