Hello again,
Regarding the combat on 20/02/39, the info from Russian sources are like the one presented nicely by Kirill. However according to Chinese/Taiwanese info, four of the claims were credited to four individual pilots for which they were decorated. Thus it's not certain that Abramov should be credited with these claims. All Russian sources I've seen states only that nine aircraft were claimed in total. Actually I never seen anything close to official Russian combat reports from China.
See my site at:
http://surfcity.kund.dalnet.se/sino-japanese-1939.htm
Best wishes/Håkan