2nd Year into a Foundation Degree I must have purchased over 20 books for my bookshelf, You get to realise that there are some that you turn to more often that others, THIS IS ONE! They've made complicated issues easier to read, personally I look in the index and go to the related pages rather than read the whole section and have referred to it time and again in my assignments. I have found it very useful.
I would suggest that managers and supervisors should have one to, a good reference for them.