Anas, I., Yulliawati, T. and Heinzemann, J. (2001) “Double Inoculation of Rhizobium and Arbuscular Mycorrhyzal fungus to Improve The Growth of Yam Bean”, Jurnal Ilmu Tanah dan Lingkungan, 2(2), pp. 18–22. doi:10.29244/jitl.2.2.18-22.