References
- Artschwager Ernst. Contribution to the morphology and anatomy of Guayule (Parthenium argentatum). U. S. Dept. Agr. 1943; 1–33, Tech. Bull. No. 842
- Hall H. M., Goodspeed T. H. Rubber plant survey of western North America. Univ. Calif. Pub., Botany 1919; 7: 159–278
- Johansen D. A. Plant Microtechnique. McGraw-Hill Book Co., New York 1940
- Lloyd F. E. Guayule, rubber plant of the Chihuahuan desert. Carnegie-Institution of Wash. 1911; 1–213, Pub. No. 139