Are you certain there are that many editions? The “1st edition” at the publisher site is the same ISBN13 as the “2016 edition” listed above and the same as the “2011” edition at https://www.directtextbook.com/isbn/9781935782056
The only “14th” I can find is at https://www.facultybooks.com/books/isbn/9781941552247.html, which is software/electronic book
Perhaps contact the professor to clarify.