Papers and Books on
Functional Logic Programming

You can also look here for papers on functional logic programming which are stored in Jon Hill's Functional Programming Archive

Other sources:

• A survey on functional logic programming which contains a lot of references:
  M. Hanus: The integration of functions into logic programming, Journal of Logic Programming, 1994
• A book on higher-order functional logic programming:
  C. Prehofer: Solving Higher-Order Equations, Birkhauser PTCS Series, 1997