Bulletin annuel de l' Institut météorologique central de Bulgarie.
Institut météorologique central de Bulgarie.
[s.n.] : The Institute,
1929-1930.
Merges with the annual supplement to the Bulgarian version of the bulletin (title unknown) to form : Godisenʺzemledělsko-meteorologičenʺ bjuletiiʺ.
Bulletin mensuel de l' Institut météorologique central de Bulgarie
Godisenʺzemledělsko-meteorologičenʺ bjuletiiʺ