Filtering the EYB Library by the ethnicity 'Hungarian' produces a much bigger list than debkellie's link (which uses 'Hungary' as a keyword in the search dialog box), but only a few of those are on many members' bookshelves. The most widely held is George Lang's Cuisine of Hungary, which for a long time after its publication in 1971 was *the* English-language authority on the subject.
Very much due to the smash success of Julia Child's Mastering the Art of French Cooking, the 1970s were filled with cookbooks that gave U.S. cooks a comprehensive introduction to other cuisines: Diana Kennedy for Mexican, Paula Wolfert Moroccan, Irene Kuo Chinese, Marcella Hazan Italian, etc. Most are still among the must-reads for anyone seriously exploring the particular cuisines, and I'd put Lang's book in that category. He was an excellent writer, a genuine authority (the book has 100+ pages of history and description of Hungary's regions and foodways before it gets down to the recipes), and there were few others focusing on Hungarian food in the succeeding decades; TCOH was reissued again and again.
My parents bought it when it first came out, more for enjoyment and learning than cooking, and I've kept it for the same reason -- though the extent to which the pages have darkened makes it harder to read now (shame on Crown Publishers for cheaping out on paper quality). Given its status as a classic, I bet at least one of the reissues was made to hold up better.