Sourcebook rhymes with:
passbook, bankbook, checkbook, cookbook, guidebook, handbook, hornbook, jokebook, logbook, matchbook, notebook, omnibook, overbook, passbook, pocketbook, powerbook, redbook, rulebook, schoolbook, scrapbook, sketchbook, storybook, subnotebook, textbook, yearbook
Sourcebook sounds like:
sarajevo's, sarcophagus, sarejevo's, schwarzkopf's, skrzypek