Příruční slovník naučný (PSN, freely translated into English as Small dictionary of facts) was a four volumes encyclopedia in Czech language published in Czechoslovakia between 1962 – 1966. The encyclopedia was published by the Czechoslovak Academy of Sciences. The aim was to displace the older Otto's encyclopedia by a new work, fitting the political views of the Communist Party of Czechoslovakia. Apart from traditional items it contains a large amount of (very flattering) information about the worldwide communist movement and its leaders, and about countries of the Eastern Bloc.