Schep LJ, Temple WA, Butt GA, Beasley MD (2009). «Ricin as a weapon of mass terror--separating fact from fiction». Environ Int35 (8): 1267–71. doi:10.1016/j.envint.2009.08.004. PMID19767104.
Schep LJ, Temple WA, Butt GA, Beasley MD (2009). «Ricin as a weapon of mass terror--separating fact from fiction». Environ Int35 (8): 1267–71. doi:10.1016/j.envint.2009.08.004. PMID19767104.