References
- Borcherds , R.E. 1986 . Vertex algerbras, Kac-Moody Algebras, and the Monster . Proc.Natl.Acad.Sci.USA , 83 : 3068 – 3071 .
- Dong , C. , Lin , Z. and Mason , G. On Vertex operator algebras as slz-module
- Frenkel , I. , Lepowsky , J. and Meurman , A. 1988 . Vertex operator algebras and the Monster Monster, Pure and applied math. , Vol. 134 , Academic Press .
- Li , H. Symmetric invariant bilinar formsa on vertex operator algebras , J. Pure appl. ALgebra .