When there are two or three authors they should all be noted in the text

Directly using an and

Davis and Taddle (2001) find…

Or indirectly

Recent research (Davis and Taddle, 2001) suggests that…

For two or three authors……..

In 1992, research undertaken in Chelsea (Deeves and Jenings, 1985) showed that…

Further research (Mentle, Smith and Diane, 1973) showed

Where two or three authors collaborate for a publication they should all be listed in the order in which their names appear in the original publication