principal applicants principal application principal architect principal architects principal area principal areas principal artist principal aspects principal asset principal assistant principal author principal authors principal axes principal axis principal balance principal beneficiaries principal bowin principal brown principal business principal called principal can principal cast principal categories principal cause principal causes principal cellist principal challenges principal changes principal character principal characteristic principal characteristics principal characters principal chief principal church principal cities principal city principal claim principal collins principal commercial principal component principal component analysis principal components principal components analysis principal concern principal concerns principal conclusions principal conductor principal consecrator principal consultant principal contractor principal crop principal crops principal dana principal dancer principal dancers principal data principal de principal deputy principal designer principal difference principal differences principal dimensions principal direction principal directions principal director principal driver principal durbin principal duty principal economic principal elements principal enemy principal engineer principal entrance principal european principal executive principal exports principal factor principal factors principal feature principal features principal field principal figgins principal financial principal focus principal food principal form principal forms principal function principal functions principal goal principal goals principal green principal guest conductor principal had principal has principal i principal ideal principal industries principal industry