References should be listed alphabetically and chronologically, such that:
 - Schmidt, J. (1995) comes before Schmidt, J. (2004)
 - Schmidt, J. (2004) comes before Schmidt, W. (1995)

Single author papers come before double author papers which come before
multiple author papers, such that:
 - Schmidt (1995) comes before Schmidt and Smith (1995) which comes before
Schmidt and Waight (1995)
 - Schmidt and Waight (1995) come before Schmidt, Waight and Brown (1995)

Multiple author papers are arranged strictly chronologically, such that
Schmidt, Waight and Brown (1995) comes before Schmidt, Brown and Waight
(2004).

If several multiple author papers with the same first author were
published in the same year, they are distinguished using \"a, b, c\" etc.,
based on the order they appear in the text.