As a leading authority on halakha he authored many important teshuvot (responsa), many of which were published in his influential "Responsa and Halakhic Studies". From the 1950s to 1970s, he wrote a comprehensive guide to Jewish law which was used to teach halakha at the Jewish Theological Seminary of America. In 1979 he assembled this into "A Guide to Jewish Religious Practice", which is used by laypeople within Conservative Judaism.