[setgree]

It’s also not correct; et al. is conventionally applied to three or more authors (it means “and others,” plural)

[trvz]

No, plural can’t be deduced from how it is written.

[cperciva]

"et alia" usually means "and others", but technically in Latin "alia" can be either plural neuter or singular female!

[setgree]

Pardon, you’re right