H. W.  Pfeifer, ?The status of the name Aristolochia durior Hill?, Baileya, vol. 10, pp. 5 - 7, 1962.

H. W.  Pfeifer, ?Revision of the north and central American hexandrous species of Aristolochia (Aristolochiaceae)?, Ann. Missouri Bot. Gard, vol. 53, pp. 115 - 196, 1966.