Dutta, T.K., Das, M.L. (2007)

Bulletin of the Malaysian Mathematical Sciences Society. Second Series

Akram, Muhammad (2007)

International Journal of Mathematics and Mathematical Sciences

Ference Szász (1971)

Monatshefte für Mathematik

Lu, Dancheng, Wu, Tongsuo (2008)

Sibirskij Matematicheskij Zhurnal

Günter Törner, Christine Bessenrodt (1990)

Forum mathematicum

Chen, Huanyin, Chen, Miaosen (2003)

The New York Journal of Mathematics [electronic only]

Günter Törner, Miguel Ferrero (1995)

Forum mathematicum

Weinert, H.J., Sen, M.K., Adhikari, M.R. (1996)

Mathematica Pannonica