Data Views Total Plants: 1 CSV Excel PDF Click on column headings to sort table by that column Plant Part Low PPM High PPM StdDev *Reference Tribulus terrestris Plant -- -- ANON. 1948-1976. The Wealth of India raw materials. Publications and Information Directorate, CSIR, New Delhi. 11 volumes. *Unless otherwise noted all references are to Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.