Frazeologichen rechnik na bŭlgarskii︠a︡ ezik /
Nicheva, K.
Spasova-Mikhaĭlova, S.
Cholakova, Kr.
Sofii︠a︡ :  Bŭlgarska Akademii︠a︡ na Naukite, 
1974-1975.
Bulgarian language