I was self taught using Vestal - Craft of Photography for my B&W education starting at age 15. Soon thereafter I discovered Hedgecoe in my small town library, and from him learned how to work effectively capturing colour.
I now passively collect older photo books as I come across them atht he right price, and have quite afew of his in my collection.
It is not really a surprise, given how well most of his books sold. The nice part though, is that once you get over that the gear mentioned in the book may be 30 yeas old, the basic concepts being advanced are still very viable today.
Most of Hedgcoe's books draw from Langford who he worked with & who's books were the a min academic text books in the UK for over 30 years. The team behind the Hedgecoe books, and it was very much a team effort probably get overlooked these days, but I liased with some of them when sorting out my small collaboration to Advanced Photography.