Limmanont, C., S. Ponglowhapan, P. Tanhan, T. Sirinarumitr, and K. Sirinarumitr. “Fetal Head Diameter in Dogs and Cats Measured by Radiography and Ultrasonography”. The Thai Journal of Veterinary Medicine, vol. 49, no. 2, June 2019, pp. 175-82, https://he01.tci-thaijo.org/index.php/tjvm/article/view/223909.