Population genetics: A new apportionment of human diversity
N.H. Barton, Current Biology 7 (1997) 757–758.

Speciation: more than the sum of its parts
N.H. Barton, in:, Current Biology, Cell Press, 1996, pp. 1244–1246.

Why species and subspecies?
N.H. Barton, Current Biology 3 (1993) 797–799.