WILLIAMS, G. A., BOLEN, M. C., & DOERHOFF Ray B. (1973). Challenges to science physical science. Wbster Division, McGraw-Hill Book Company.
Chicago (17e ed.) BronvermeldingWILLIAMS, George A., Max C. BOLEN, en DOERHOFF Ray B. Challenges to Science Physical Science. New York: Wbster Division, McGraw-Hill Book Company, 1973.
MLA (9e ed.) BronvermeldingWILLIAMS, George A., et al. Challenges to Science Physical Science. Wbster Division, McGraw-Hill Book Company, 1973.
Let op: Deze citaties zijn niet altijd 100% accuraat.