How can I get ALL of my Outlook calendars to sync to android?

I have multiple calendars in my outlook.com account - personal, work, holiday, birthdays, etc. Only my primary (personal) outlook calendar is syncing to my android phone. How can I get all of them to sync, or do I just have to use one for everything if I want my appointments to show up in my phone? I  am just syncing the account to my phone, not using the Outlook app because I prefer to have a combines inbox with all of my various accounts rather than having to open multiple apps to check each one. Email syncs just fine and so does the main calendar, but the work calendar not syncing is a problem.