[1] Aigner M. Combinatiorial theory [M]. Berlin:Springer-verlag 1979. [2] Wan Zhexian. Geometry of classical groups over finite fields [M]. Lund:Studentlitteratur/Bromley:Chartwell-Bratt 1993. [3] HUO YUANJI, LIU YINGSHENG, WAN ZHEXIAN. Lattices generated by transitive sets of subspaces under finite classical groups I [J]. Communications in Algebra 1992, 20. [4] 万哲先, 霍元极. 有限典型群子空间轨道生成的格 [M]. 北京:科学出版社 1997.