This book is an absolute god sent from famous illustrator and author Andrew Loomis who's teachings today have been reflected upon an entire generation of artists and will continue to do so.
This book is another god sent from the same era as Andrew Loomis. I don't care what kind of artist you want to be because this book will not only teach you how to construct human anatomy but design it as well which is an essential skill set for all kinds of artists.
So This book mainly just teaches you how to draw and design the human head from live models. Loomis goes into detail about his design process for drawing the head and the facial features, which was a very unique that has been adopted by the greatest artist in our modern era. With all that being said, this is NOT an anatomy book. I would recommend you have supplementary books that solely focus on anatomy.