It is simple. If you don't have a guarantor there are steps to take (form, notary etc.). References are people you have known for at least 2 years. They don't have to be Canadian citizens nor live in Canada.
It's a dumb requirement and people who think this archaic system is great are also dumb. The only thing you should need to get your passport after going through the whole citizenship process is your citizenship certificate, not a Mafia like system where you get some jerkoff to vouch for you in front of the government.