DamayanthiE., Yopi.., HasinahH., SetyawardaniT., RizqiatiH., and PutraS. “Karakteristik Susu Kerbau Sungai Dan Rawa Di Sumatera Utara”. Jurnal Ilmu Pertanian Indonesia, Vol. 19, no. 2, Dec. 2014, pp. 67-73, https://journal.ipb.ac.id/index.php/JIPI/article/view/8799.