I started reading Hucho's second edition. I only got halfway into the 2nd chapter when the book I meant to order arrived (the fourth edition). Keep an eye out if your purchasing. Just by flipping through it seems th 4th edition has a lot more content (918 pages vs 576) and is a lot more up to date. The second edition was published in 1987 vs the fourth edition in 1998. Here are the two.
Second edition
Fourth edition
