Penrose, R. G., & Holubec, I. (1973). Laboratory study of self-sealing limestone plugs for mine openings. Office of Research and Monitoring, U. S. Environmental Protection Agency.
Chicago-Zitierstil (17. Ausg.)Penrose, Ray G., und Igor Holubec. Laboratory Study of Self-sealing Limestone Plugs for Mine Openings. Washington, DC: Office of Research and Monitoring, U. S. Environmental Protection Agency, 1973.
MLA-Zitierstil (9. Ausg.)Penrose, Ray G., und Igor Holubec. Laboratory Study of Self-sealing Limestone Plugs for Mine Openings. Office of Research and Monitoring, U. S. Environmental Protection Agency, 1973.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.