Machlup, Fritz. “Friedrich von Hayek's Contribution to Economics.” The Swedish Journal of Economics 76 (December 1974): 498–531.
“Some of Hayek’s 15 books appeared also in foreign translations. There are altogether 20 foreign language editions (in 11 different languages), so that the combined count comes to 35 books. The bibliography contains 10 pamphlets, and 10 books edited or introduced by Hayek. This brings the number of items listed on file cards of library catalogs to 55.”