 His speciality was modern Latvian history, especially of the Soviet Union and the Latvian Riflemen.His ground-breaking work on Jukums Vācietis and the Latvian Riflemen's role in the Bolshevik Revolution paved the way for further research on this subject by other Latvian émigré historians, notably the early works of Andrew Ezergailis.His book "Zili stikli, zaļi ledi" (Blue glass, green ice; 1968) describes his experience researching the story of Vācietis.