scott robertson's how to draw, marshall vandruff perspective course, perspective made easy ernest norling, and a few other books. just get a new masters academy subscription and do their linear perspective master course. its the most complete lectures on perspective there is. Im currently studying it having just started this week and I wish I had just done this instead of all the other stuff because I am having to sit through a lot of content I know just to get to the nuggets of perspective technique he drops in the lectures that are usually overlooked in books. Erik Olson is possibly the most well versed artist in terms of perspective and teaching that you could possibly find. He demos everything.
