Kasch and Mader developed the theory of the total over the last 10–20 years and put it together for the first time in this book.
Friedrich Kasch
Group Theory Modules Rings Abelian group algebra endomorphism ring Group theory homomorphism ring torsion
From the reviews:
“The book is self-contained, well organized and nicely written, making it a very effective introduction to the subject at hand: the total.” (MAA REVIEWS)