Question: Which territory did Roman von Ungern-Sternberg's forces and the Transbaikal fight over? 
Sentence (from "36th Rifle Division (Soviet Union)"): The division was first formed as the 36th Rifle Division (ru: 36-я стрелковая дивизия) based on the 9th Army's expeditionary division on 19 July 1919.
Relevant evidence: No