In the United States of America, Mein Kampf has been published several times. Even though the book was registered for protection under the U.S. Copyright Act already in the 1920's, and the United States has since ratified the Berne Convention, there is no indication that present publication is taking place with permission from the copyright holder, whomever that may be. Even a direct inquiry to Houghton Mifflin, one of the publishers involved, has failed to produce a clear answer as to whether any royalties are being paid.