12 Mar 2003 Dear professor, I study homotopy groups of exceptional Lie groups. I want to learn group structures of these groups; G2=? , F4=? etc. If you help me I will be greatfull. Mehmet Citil Ankara Unv. Fen Fakultesi Matematik Bolumu Tandogan-ANKARA TURKEY Mehmet.Citil@science.ankara.edu.tr