(NpROHODKA WERTIKALXNYH STWOLOW [AHT OBY^NYM SPOSOBOM (B:s (Nu^EBNOE POSOBIE (B/s - (NpOKROWSKIJ(B, (NnIKOLAJ mIHAJLOWI^s ((NmOSKWA (B:s (NuGLETEHIZDAT(B,s, 1959)
Keywords: (NgORNOE DELO (B- (N{AHTNYE STWOLY (B- (NpROHODKAs; (NkAMENNYE UGLI W CELOMs