M. Karadaev, I. Fasulkov, N. Vasilev, K. Hristov, and I. Fedev, “THREE-DIMENSIONAL (3D) ULTRASOUND INVESTIGATIONS FOR MONITORING OF THE SECOND AND THIRD PREGNANCY TRIMESTER IN GOATS”, Tradit. Mod. Vet. Med., vol. 4, no. 2, pp. 72–76, Nov. 2019.