มีแก้ว ส. “Factors associated with repeated pregnancy in postpartum adolescent mothers under 20 years of age Ratchaburi Province”. Hua Hin Medical Journal, vol. 3, no. 2, Feb. 2019, pp. 38-48, https://he01.tci-thaijo.org/index.php/hhsk/article/view/175253.