Cross-Book Additional Resources: How Much Do I Have to Have?

[mechaPoet]

I couldn't find anything to answer this question with a forum search, or under the guidelines for Additional Resources, so I apologize if the answer to this is already clear and available. :P

I just picked up the Advanced Class Guide, and with all the archetypes and feats, there are a number of ways to get other classes' features. However, if I don't own certain books, how much of the features can I use if they are referenced?

Example 1: There's a Hunter archetype that gains a vermin companion. However, it says to reference the list of vermin companions in Ultimate Magic (if I remember correctly--I don't have access to my PDF at the moment), but I don't have that book. Can I use this archetype?

Example 2: There's an Arcanist archetype that gets a Black Blade a la the Magus archetype. Again, I don't have Ultimate Magic, so can I use this archetype (I'm not sure if the archetype provides the Black Blade info, or just says to reference UM)?

[Dylos]

If you cannot point your GM to the official rules of an ability, you cannot use that ability, if those rules are in a book that you lack access to, then you cannot use them.

So if you are using Blade Adept in PFS you need to have Ultimate Magic as well as the Advanced Class Guide. This is the same if you wanted to play a Cavalier (Advanced Players Guide) with the Daring Champion (Advanced Class Guide) archetype.

[The Fourth Horseman]

Unfortunately, my interpretation (and this may have been clarified officially already, I'm not sure) is that you would need the book referenced, otherwise you are using rules that you can't PFS legally reproduce for the GM should they ask about your class abilities / feats.