How many monks required to ordain or create new Sangha? How many monks does it take to ordain a new monk? How many monks does it take to create a new Sangha?

I've read this before, now I can't find it.

I think these are very old rules &amp; are similar across different traditions.

Note. I already know that schism is considered the worst thing in the universe by traditional Buddhism.
Quorum of 10 of 10 years standing, 5 in border areas. 5 is the quorum generally outside India. [page 108, Theravada Buddhism: A Social History from Ancient Benares to Modern Colombo (The Library of Religious Beliefs and Practices) 2nd Edition
by Richard F. Gombrich]

The quorum to perform a patimokkha ceremony is 4 [page 110, Theravada Buddhism: A Social History from Ancient Benares to Modern Colombo (The Library of Religious Beliefs and Practices) 2nd Edition
by Richard F. Gombrich]