D. A. Patil, C. S. Bagewadi, and D. G. Prakasha. “On Generalized φ -Recurrent Para-Sasakian Manifolds”. Journal of International Academy of Physical Sciences, vol. 15, no. 1, Mar. 2011, pp. 1-10, https://www.iaps.org.in/journal/index.php/journaliaps/article/view/570.