Albania   2 studies
Andorra   2 studies
Austria   1248 studies
Belgium   1978 studies
Bosnia and Herzegovina   35 studies
Bulgaria   325 studies
Croatia   248 studies
Czech Republic   952 studies
Denmark   1665 studies
Estonia   245 studies
Finland   807 studies
Former Yugoslavia   4 studies
France   3734 studies
Germany   4395 studies
Greece   584 studies
Hungary   830 studies
Iceland   40 studies
Ireland   346 studies
Italy   2487 studies
Latvia   210 studies
Lithuania   251 studies
Luxembourg   27 studies
Macedonia, The Former Yugoslav Republic of   28 studies
Malta   12 studies
Monaco   1 study
Montenegro   2 studies
Netherlands   2217 studies
Netherlands Antilles   1 study
Norway   1015 studies
Poland   1376 studies
Portugal   495 studies
Romania   532 studies
Serbia   138 studies
Serbia and Montenegro   60 studies
Slovakia   433 studies
Slovenia   130 studies
Spain   2189 studies
Sweden   1292 studies
Switzerland   1450 studies
United Kingdom   3323 studies