Poonpilai Suwanarit, Rapeepun Chewatanaruk, and Amara Chantanao. 1992. “A comparative study on Effects of Four Species of VA Mycorrhizal Fungi on Growth of Corn”. Agriculture and Natural Resources 26 (2). Bangkok, Thailand:203-8. https://li01.tci-thaijo.org/index.php/anres/article/view/241776.