Style 1.
A typical reference in the list of references would be
[3] L. Grüschen, `Pseudo-quasi-ergodic theorems', J. Austral. Math. Soc. 4 (1960), 2-3.
A corresponding reference in the text would be: Grüschen [3]; or [3,4,9]; or Grüschen [3, Theorem 1].
Style 2.
A typical reference in the list of references would be
[GBP] G. B. Preston, `Pseudo-quasi-ergodic theorems', J. Austral. Math. Soc. 40 (1960), 321-342.
A corresponding reference in the text would be: Preston [GBP]; or ([GBP, KG, GHL]); or Preston [GBP, Proposition 2].
In each style, the list of references should be in alphabetical order of surnames of first authors.