– Riot Games
Anatomy for Sculptors books are a great reliable resource that will make this knowledge easy to understand and accessible. There are a wide range of breakdowns from simple, isolated forms to more complicated, from young to old, from human to animal anatomy. Not only do they make the process easier, they also provide new ways of looking at shapes, structure and flow.
I highly recommend incorporating this resource in your workflow even if your preferred medium is not sculpting.