Saxon genitive and "et al."

I am writing a scientific paper. In this context, it is usual to cite other works with the last name of the first author followed by "et al." when there are many. If I want to use a possessive form, how should I use the Saxon genitive?

For example, is "Smith's et al." correct?

Solution 1:

First of all, et al. should be in italics. That said, the common way to refer to a publication like that would be:

Smith and coworkers'...

or

Smith and colleagues'

Et al. means and others, it is an abbreviation of the latin et alii. If you really really wanted to use it in the possessive, you would write

Smith et al's

but don't do that, it is ugly and unclear. Paraphrase, use and coworkers or similar constructs.