ERIC report: The affirmative and the negative - Work, William and Demo, Mary Penasack (Communication Education, 1980)
https://katalog.adlr.link/Record/ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuMTA4MC8wMzYzNDUyODAwOTM3ODQxMQ