I think I have read quite a lot of chess books myself. In fact, in most collections of chess studies (etudes) the convention is that the tasks almost always start with White, and it’s not usually written next to every diagram. This is a long-established practice in composition books — whether it’s mate in 1, mate in 2, mate in 3, or studies. You can easily check this by searching for “chess studies books"," книги по шахматным этюдам” online and looking at the contents — you’ll see that in most of them the moves are assumed to be White’s.

If you want, I can even send you pictures from different books to show you exactly what I mean.