Chiang, Y. C. (2005). Array Structure Recognition in Flatten Layout [master's thesis, Yuan Ze University]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0009-0112200611321741
Bell, H. E., & Yaqub, A. (2007). On Generalized Periodic-Like Rings. International Journal of Mathematics and Mathematical Sciences, 2007(), 291-295. https://doi.org/10.1155/2007/29513