Garg, K M, et al. “Pharmacological Evaluation of Phosphodiesterase Inhibitors As Potential Tocolytic Agents in Buffaloes (Bubalus Bubalis)”. The Indian Journal of Animal Sciences, vol. 75, no. 2, Feb. 2005, https://epubs.icar.org.in/index.php/IJAnS/article/view/8119.