1. An Introduction to Gröbner Bases;Adams,1994
2. Nilpotent normal forms and representation theory of sl(2,r);Cushman,1986
3. Nilpotent normal form in dimension 4;Cushman,1987
4. A survey of invariant theory applied to normal forms of vectorfields with nilpotent linear part;Cushman,1990
5. Normal form for the (2;n)-nilpotent vector field, using invariant theory;Cushman;Physica D,1988