What is correct Nicholas' or Nicholas's

It is pronounced 'Nicholas-ess', and actually, modern names should take the 's: Nicholas's. Its omission is only used for certain classical and Biblical names: Moses', Jesus', Socrates'.

The former, Nicholas', is correct.
Students: We have free audio pronunciation exercises.

So do you pronounce it as "Nicholas-ess" or just "Nicholas”?
 Mister Micawber's reply was promoted to an answer.
Nicholas's, pronounced Nicholas-iz.

Teachers: We supply a list of EFL job vacancies