1. U. Laba, (Lerak (Sapindus rarak) Soap Substitute Industrial Plant) Center for Research and Development of Industrial Plants, Jakarta (2009) (in bahasa)
2. W.H. Biecher, Garden of Hesperides (The Anglo Egyption Bookshop. Cairo, 1960)
3. Sugianto, Toxic Plants (Widjaya Publisher. Jakarta, 1984)
4. K. Hostettmann, and A. Marston, Saponins (Cambridge University Press, Cambridge, New York, 1995)
5. J.B. Harborne, Phytochemical Methods: Guidelines for Modern Methods of Analyzing Plants. (ITB Publisher, Bandung, 1996), pp. 123–129. (in bahasa)