Consists of a preface and five works, each has its own title page and separate pagination. 1. About patients (Pechenegs). 2. Historical reasoning about the Khazars. 3. Historical reasoning about Galicia and Lodomiria. 4. Historical reasoning about Finns. 5. Historical reasoning about the Slavs, their origin and ancient dwellings. Peter Friederik Sum (Danish Peter Friderich Suhm; 1728-1798) - Danish historian. He graduated from the University of Copenhagen and in 1751 entered the civil service, having worked for several years in remote Trondheim. Since 1781, chairman of the Danish Royal Society for the Study of Russian History.