1. Ali, F.: Fischer–Clifford matrices of the non-split group extension $$2^{6}{^{\cdot }}U_{4}(2)$$. Quaest. Math. 31(1), 27–36 (2008)
2. Basheer, A.B.M.: Clifford–Fischer Theory Applied to Certain Groups Associated with Symplectic, Unitary and Thompson Groups, PhD Thesis, University of KwaZulu-Natal, Pietermaitzburg (2012)
3. Basheer, A.B.M., Moori, J.: Fischer matrices of Dempwolff group $$2^{5}{^{\cdot }}GL(5,2)$$. Int. J. Grp. Theory 1(4), 43–63 (2012)
4. Basheer, A.B.M., Moori, J.: On the non-split extension group $$2^{6}{^{\cdot }}Sp(6,2)$$. Bull. Iran. Math. Soc. 39(6), 1189–1212 (2013)
5. Basheer, A.B.M., Moori, J.: On the non-split extension $$2^{2n}{^{\cdot }}Sp(2n,2)$$. Bull. Iran. Math. Soc. 41(2), 499–518 (2015)