Multilocus clines
N.H. Barton, Evolution; International Journal of Organic Evolution 37 (1983) 454–471.

The structure of the hybrid zone in Uroderma bilobatum (Chiroptera: Phyllostomatidae)
N.H. Barton, Evolution 36 (1982) 863–866.

A chromosomal cline in the grasshopper Podisma pedestris
N.H. Barton, G. Hewitt, Evolution; International Journal of Organic Evolution 35 (1981) 1008–1018.