Varisco, D. M., & ʻUmar ibn Yūsuf, S. o. Y. (1994). Medieval agriculture and Islamic science: The almanac of a Yemeni sultan. University of Washington Press.
Chicago Style (17th ed.) CitationVarisco, Daniel Martin, and Sultan of Yemen ʻUmar ibn Yūsuf. Medieval Agriculture and Islamic Science: The Almanac of a Yemeni Sultan. Seattle: University of Washington Press, 1994.
MLA (9th ed.) CitationVarisco, Daniel Martin, and Sultan of Yemen ʻUmar ibn Yūsuf. Medieval Agriculture and Islamic Science: The Almanac of a Yemeni Sultan. University of Washington Press, 1994.
Warning: These citations may not always be 100% accurate.