Below, left to right, top to bottom:
All the following are from Hungary and bear the following dates, in order:
1899, c 1905, 1888, 1912, pre 1902, pre 1902, 1898, 1906, 1913, 1914, c 1900, pre 1902, pre 1902, early 20thC
All the following are from Hungary and bear the following dates, in order:
1899, c 1905, 1888, 1912, pre 1902, pre 1902, 1898, 1906, 1913, 1914, c 1900, pre 1902, pre 1902, early 20thC
The following are Czechoslovakia. The first ten are of the Romani Ghetto in Prague which seems to have existed from early 1900s (perhaps before) into WW2 and then resumed after WW2. The fifth is of the Jewish Ghetto there.
The following are from Rumania:
The following are from Serbia:
The following are from Macedonia:
The following are from Yugoslavia or Bosnia
The following are from Bulgaria:
The following are from the Ukraine:
The following are from Russia:
The following are from Poland

The following are from Turkey
The following are unspecified Eastern Europe: