I get my references everywhere, from shapes to pornography but by “reference”, I mean to understand/observing anatomy clearly (like perspective, twists and turns, overlap, poses, human muscles, bones, the “how” and the “what” questions, etc which porn has a lot of it) and not literally getting the ideas and poses from porn lol. So the BEST way to get anatomy is getting as much references as you can and try and understand them. A good way to practice is to draw different basic figure poses as much as you need to until you get them right.