Riga 1927-1928 (10 October 1927- 6 February 1928) Riga Chess Club Championship. <Petrovs finished 4th>, behind N. Elisons, A. Taube and E. Bauman, scoring 9.5/14. "Latvis", October 7, 1927, p. 7; "Сегодня", February 10, 1928, p.6; "Rigache Rundschau", March 10, 1928, p.13