Battles of Khalkhin Gol

After the occupation of Manchuria in 1931, Japan turned its military interests to Soviet territories that bordered those areas. The first major Soviet-Japanese border incident, the Battle of Lake Khasan, happened in 1938 in Primorye. Clashes between Japanese and Soviet forces frequently occurred on the border of Manchuria.

• http://en.wikipedia.org/wiki/Battles of Khalkhin Gol
• Page 25 - Beevor, A., 1998, Stalingrad: The Fateful Siege: Penguin Group, New York, 494p.