classification of poker math books

I was wondering why are there so many Hold'em math titles on the market, since the mathematics is only one. I guess the answer is that each book has its own coverage on the math of the game (which is wide), according to its author's fields of expertise. Some of them are successful or experienced poker players and inclined more on strategy than on pure math, others have some technical background and their approach of the poker math is rather statistical then analytical, and few of them have a strong mathematics background, making their books to look like real applied math courses. Well, there is also a last category of authors: poker players that still master their high-school math, found that few simple probability calculations can fill tens of pages, teaching others how to do them can fill hundreds of pages and so came up with a book on poker math. I will ignore this latter category in my current review.
The issue is not to rank all these titles together in a top-5 or -10 list, but ranking them by several criteria, of which I see coverage of Hold'em math, ease of understanding, and usefulness in strategy as the most relevant. I guess such classifications would be useful for someone who wants o pick a book or two per his/her needs. So please improve my lists below. I chose the following titles as relevant and labeled them with numbers, then in my classifications I only used their numbers (the order in the first list is given by their publication year):

Hold'em Odds Book (Petriv) – 1
Weighing the Odds in Hold'em Poker (Yao) – 2
Texas Hold'em Odds and Probabilities: Limit, No-Limit, and Tournament Strategies (Hilger) – 3
The Mathematics of Poker (Chen) – 4
The Math of Hold'em (Moshman) – 5
Poker Math that Matters: Simplifying the Secrets of No-limit Hold'em (Gaines) – 6
Texas Hold'em Poker Odds for Your Strategy, with Probability-Based Hand Analyses (Barboianu) – 7

Now, my classifications are:
By usefulness in strategy: 6, 2, 3, 5, 7, 4, 1
By ease of understanding: 3, 2, 4, 6, 5, 1, 7
By coverage of Hold'em math: 7, 1, 5, 4, 2, 6, 3
Feel free to add other criteria, titles, or change rankings, of course.