sentences:  His textbooks of Ukrainian history were widely used both in Galicia and also among Ukrainians in North America.At this time, he also prepared a new scholarly "History of Ukraine" which was only published in 1949 in the west under the pseudonym 'Ivan Kholmsky'.During the Soviet period, Krypiakevych was known as an expert on the era of Khmelnytsky and on the occasion of the Three Hundredth Anniversary of the Treaty of Pereiaslav between the Cossacks and the Russian Tsar his "Bohdan Khmelnytsky" appeared in a very luxurious edition (1954).