The Journal of Functional Programming (JFP)’s LaTeX styles aren’t
compatible with natbib. But I like natbib! So this package is a
hack to make jfp1.cls and jfp.bst compatible with natbib. You have to
include it after including natbib. As a hack, be warned that this package is
probably somewhat fragile.
Usage:
\documentclass{jfp1}
% ...
\usepackage{natbib}
% ...
\usepackage{jfp-natbib-hack}
% ...