The present paper deals with weakly symmetric and weakly Ricci symmetric trans-Sasakian manifolds. The existence of weakly Ricci symmetric trans-Sasakian manifolds is ensured by an example.
Kõlli, R., Ellermäe, O., Köster, T., Lemetti, I., Asi, E., & Kauer, K. (2009). Orgaanilise süsiniku varud Eesti muldades. Estonian Journal of Earth Sciences, 58(2), 95-108. https://www.airitilibrary.com/Article/Detail?DocID=17367557-200906-201011080063-201011080063-95-108