Abujabal, H. A. S., M. A. Obaid, and M. A. Khan. 2018. “On Commutativity of Rings With Constraints Involving a Nil Subset”. Proyecciones (Antofagasta, On Line) 15 (1):91-99. https://doi.org/10.22199/S07160917.1996.0001.00005.