1. T. Feder, P. Hell, J. Huang, List homomorphisms to general graphs, Manuscript, 1996
2. List homomorphism to reflexive graphs;Feder;J. Combin. Theory B,1998
3. Monotone monadic SNP and constraint satisfaction;Feder,1993
4. Retractions de graphes, Ph.D. Thesis;Hell,1972
5. On the complexity of H-coloring;Hell;J. Combin. Theory B,1990