5Proctor R. Ginseng: Industry, Botany, and Culture. Horticultural Reviews, 1987,9:187.
6Wright R J, Witwowski J F, Echtenkamp O. Efficacy and Persistence of Steinernema sp. Applied through a Center-pivot Irrigation System Against Larval Corn Rootworms. J Econ Entomol,1993,86(5 ) : 1348.