For Papaver
Kadereit. 1993. In Kubitzki, K., J.G. Rohwer, and V. Bittrich, eds. 1993. The families and genera of vascular plants. II. Flowering plants – Dicotyledons – Magnoliid, Hamamelid and Caryophyllid families. Springer, Berlin. 653 pp. Google Scholar
Kiger, R.W. 1975. Papaver in North America north of Mexico. Rhodora 77: 410-422. Google Scholar
Kiger, R.W., and D.F. Murray. 1997. Papaver. In Flora of North America Editorial Committee. 1997. Flora of North America north of Mexico. Volume 3, Magnoliophyta: Magnoliidae and Hamamelidae. Oxford Univ. Press, New York, NY. 590 pp. Google Scholar