Gene flow past a cline
N.H. Barton, Heredity 43 (1979) 333–339.

The dynamics of hybrid zones
N.H. Barton, Heredity 43 (1979) 341–359.

A hybrid zone in the alpine grasshopper Podisma pedestris
N.H. Barton, A Hybrid Zone in the Alpine Grasshopper Podisma Pedestris, University of East Anglia, 1979.