OK, for the first one from Bulgaria:
It's a Rana sp., for sure!
There are 3 species of Rana in Bulgaria:
Rana dalmatina
Rana temporaria
Rana graeca
Rila Mts. are out of the range of R.graeca, so it's not!
The Grancar Cottage in Rila Mts. is at 2187 m a.s.l., which is pretty high for R.dalmatina. Besides,the skin on the back of R.dalmatina is smooth,unlike the skin of the frog from the photo,which has small tubercules. The only species from the 3 that has such tubercules and lives that high in the mountains is R.temporaria! Besides the snout looks shorter,less pointed and more rounded like in R.temporaria!..So,it's
Common Frog (Rana temporaria)I don't know about the others! They all look like Pelophylax ridibundus,to me!
I find Pelophylax species hard to identify!
P.S. Vlad,your frog looks both like R.dalmatina and R.temporaria! The head(snout) looks like R.temporaria but since it's a juvenille individual the proportions are not like in the adults,so it's hard to say! Do you have other pictures of that frog?