Diana Kennedy, The Cuisines of Mexico, Harper & Row, 1972.
We respect Diana Kennedy as the queen of Mexican cooking, but somehow we never connected with this comprehensive volume. We donated it to the library book sale to avoid expanding the collection to three shelves. (We gave away our Julia Child French Cooking books years ago — a similar issue there.)
Anyway, we saved our go to zucchini/chard recipe and it is saved on this site.