Sotthibundhu, Areechun, Doungjai Buntup, Channarong Sanghirun, Korbkit Cherdchu, Cheeraratana Cheeramakara, Sirintorn Chansirikarnjan, Ekapot Nimkulrat, Chesda Udommongkol, Wanna Wongmek, and Wipawan Thangnipon. 2008. “Low Serum Vitamin B12 in Alzheimerûs Patients As Detected by a Solid Phase Radioimmunoassay”. Siriraj Medical Journal 60 (2):66-68. https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/246358.