The structure and maintenance of hybrid zones as exemplified by Podisma pedestris
G. Hewitt, N.H. Barton, in:, R. Blackman, M. Ashburner (Eds.), Insect Cytogenetics, Wiley-Blackwell, 1980, pp. 149–170.

The fitness of hybrids between two chromosomal races of the grasshopper Podisma pedestris
N.H. Barton, Heredity 45 (1980) 47–59.

The hybrid sink effect
N.H. Barton, Heredity 44 (1980) 277–278.