Centralizing and commuting generalized derivations on prime rings Asif Ali; Tariq Shah — 2008 Matematički Vesnik
Factorization properties of subrings in trigonometric polynomial rings. Shah, Tariq; Ullah, Ehsan — 2009 Publications de l'Institut Mathématique. Nouvelle Série
Subrings in trigonometric polynomial rings. Shah, Tariq; Ullah, Ehsan — 2009 Acta Mathematica Academiae Paedagogicae Nyí regyháziensis. New Series [electronic only]