added some references to selectfirst
added some references to selectfirst

dstufft/sqlalchemy,robin900/sqlalchemy,alex/sqlalchemy,olemis/sqlalchemy,alex/sqlalchemy,epa/sqlalchemy,bootandy/sqlalchemy,276361270/sqlalchemy,276361270/sqlalchemy,wfxiang08/sqlalchemy,hsum/sqlalchemy,brianv0/sqlalchemy,EvaSDK/sqlalchemy,pdufour/sqlalchemy,monetate/sqlalchemy,davidfraser/sqlalchemy,ThiefMaster/sqlalchemy,sandan/sqlalchemy,bdupharm/sqlalchemy,davidjb/sqlalchemy,epa/sqlalchemy,WinterNis/sqlalchemy,robin900/sqlalchemy,j5int/sqlalchemy,bootandy/sqlalchemy,Cito/sqlalchemy,bdupharm/sqlalchemy,olemis/sqlalchemy,inspirehep/sqlalchemy,ThiefMaster/sqlalchemy,wfxiang08/sqlalchemy,davidfraser/sqlalchemy,Cito/sqlalchemy,sqlalchemy/sqlalchemy,itkovian/sqlalchemy,davidjb/sqlalchemy,elelianghh/sqlalchemy,brianv0/sqlalchemy,Akrog/sqlalchemy,halfcrazy/sqlalchemy,elelianghh/sqlalchemy,EvaSDK/sqlalchemy,dstufft/sqlalchemy,hsum/sqlalchemy,Akrog/sqlalchemy,graingert/sqlalchemy,wujuguang/sqlalchemy,pdufour/sqlalchemy,Cito/sqlalchemy,monetate/sqlalchemy,halfcrazy/sqlalchemy,j5int/sqlalchemy,inspirehep/sqlalchemy,zzzeek/sqlalchemy,graingert/sqlalchemy,WinterNis/sqlalchemy,itkovian/sqlalchemy,sandan/sqlalchemy,alex/sqlalchemy,wujuguang/sqlalchemy