During his doctorate studies, he was a visiting student for a PhD Program at McGill University, Montreal, Canada (1993–1994), and a visiting student for a PhD Program at Leiden University, Netherlands (1994–1995).
Umar | Mohd Bunyamin Umar | Umar Farouk Abdulmutallab | Abu Hafs Umar al-Suhrawardi | Veliyankode Umar Khasi | Umar's Assurance of safety to the people of Aelia | Umar's Assurance | Umar Makram | Umar ibn Hubayra | Umar Bin Hassan | Razali Umar Kandasamy | Pact of Umar | Habib Umar bin Hafiz | Ghali Umar Na'Abba | Abdullah ibn Umar |