On The Wikipedia page for Axiom of limitation of size it states that this axiom can be used to prove the axiom of union: https://en.wikipedia.org/wiki/Axiom_of_limitation_of_size
It implies the axiom schema of specification, axiom schema of replacement, axiom of global choice, and even, as noticed later by Azriel Levy, axiom of union at one stroke.
I understand the first three axioms mentioned, but I haven't been able to find anything regarding the axiom of union. Does anyone know how this axiom implies the other? Thanks in advance.