JEMF (John Edwards Memorial Foundation) is held in partial runs by some 40 libraries, the first issues mimeographed; not the easiest journal to find.
The information may be in a book by Nolan Porterfield, "Exploring Roots Music," surveying the 20 years of publication. Karnes, a sometime Baptist preacher and gospel singer, is covered in the book according to some notes found on Google.
The book was published by Scarecrow Press for $37.50; Amazon.com and others have or can locate copies.