Kircher, H. B., Wallace, D. L., & Gore, D. J. (1988). Our natural resources and their conservation (6th ed.). Interstate Printers & Publishers.
Chicago (17e ed.) BronvermeldingKircher, Harry B., Donald L. Wallace, en Dorothy J. Gore. Our Natural Resources and Their Conservation. 6th ed. Danville, Ill.: Interstate Printers & Publishers, 1988.
MLA (9e ed.) BronvermeldingKircher, Harry B., et al. Our Natural Resources and Their Conservation. 6th ed. Interstate Printers & Publishers, 1988.
Let op: Deze citaties zijn niet altijd 100% accuraat.