I can agree that I've always found the poly-literature always a bit lacking in options for singles.
I'm polyamorous by nature, but I have no interest in becoming a secondary. So where does that leave me? Kind of stuck.
My desire would be able to build a triad or a quad up from me and 3 other singles who have the same goals, because I know I will definitely want to start a family. But finding 2 or 3 likeminded people? I haven't been having any luck.