Visited many universities, education centers and participated in many Scientific Conferences in the following countries: Britain, Egypt, Ghana, Gold Coast, Algiers, Mauritania, Lebanon, Syria, Saudi Arabia, Ethiopia, Qatar, Kenya, Libya, Niger, Nigeria, Senegal, Tanzania, Tunis, Uganda, Bahrain, Zambia, Zimbabwe, Yemen, United Arab Emirates, Oman, Turkey, Pakistan, Japan, Hong-Kong, France, Germany, Netherlands, Sweden, Norway, Italy, Belgium, Poland, Greece, Yugoslavia, Austria, Switzerland, USSR, USA, Mexico, Burkina Faso , Malaysia and South Africa.