1. D. Daigle, Affine rulings and homogeneous locally nilpotent derivations, preprint.
2. D. Daigle, Locally nilpotent derivations and Danielewski surfaces, to appear.
3. Local slice constructions in K[X,Y,Z], Osaka;Freudenburg;J. Math.,1997
4. On groups of automorphisms of a class of surfaces, Israel;Makar-Limanov;J. Math.,1990
5. L. Makar-Limanov, On the group of automorphisms of a surface xny=P(z), preprint, 1996.