If you have ever read SOMETHING in Inorganic Chemistry, I am sure you have heard of F. Albert Cotton! So, apart from countless publications and other textbooks, he wrote this book to help chemists understand group theory and use it.
The importance of this book can easily be understood by the preface:
"Despite the fact that there seems to be a growing desire among chemists at large to acquire this knowledge, it is still true that only a very few, other than professional theoreticians, have done so...no book available which is not likely to strike some terror into the hearts of all but those with an innate love of apparently esoteric theory."
I tried to buy the first edition of this book (1963) and I did. Because, I think it has historical importance too.