Anthony, Ted. Chasing the Rising Sun: The Journey of an American Song. Simon & Schuster, 2007. (Includes a discussion of Alan and Elizabeth Lomax's 1937 trip to Kentucky where they recorded the song three times.)
Cohen, Anne B. Poor Pearl, Poor Girl! The Murdered-Girl Stereotype in Ballad and Newspaper. Published for the American Folklore Society by The University of Texas Press. 1973. (Study of the ballad of Pearl Bryan; there are several recordings of the song in the collection.)
Cohen, John, Mike Seeger, and Hally Wood. Old-Time String Band Songbook. Oak Publications, 1964, 1976. (Songbook produced by members of the New Lost City Ramblers, includes text and musical transcriptions of pieces in the collection.)
Feintuch, Burt. Kentucky Folkmusic: An Annotated Bibliography. University Press of Kentucky, 1985.
Garland, Jim. Welcome the Traveler Home. University Press of Kentucky, 1983. (Garland writes about his relationship with Mary Elizabeth Barnicle and Alan Lomax pp. 183-184. Their recordings of Garland are here.
Green, Archie. Only a Miner: Studies in Recorded Coal-Mining Songs. University of Illinois Press, 1972. (Discusses Mary Elizabeth Barnicle, Jim Garland, Sarah Ogan Gunning, Aunt Molly Jackson, Alan Lomax, John Lomax, James W. Day / Jilson Setters and others.)
Lomax, Alan. Assistant in Charge: The Library of Congress Letters, 1935-1945. Edited by Ronald D. Cohen. University Press of Mississippi, 2011. (Includes a selection of Alan Lomax's correspondence regarding his field work in Kentucky as well as that of Mary Elizabeth Barnicle, Paul Brewster, and John Lomax.)

Review: Lofgren, Lyle. Old-Time Herald. Vol. 12 Issue 11, June /July 2011,  pp. 50-52.
Lomax, Alan. Folk Song Style and Culture. American Association for the Advancement of Science, 1968. pp. 276, 278-299. (Includes comparison of Kentucky ballads to songs from other cultures without referencing specific performers or performances.)

Review: Wilgus, D.K. The Journal of American Folklore, Vol. 74, No. 293. Jul. - Sep., 1961, pp. 268-269. 
Lomax, Alan; Cohen, Ronald D.; Averill, Gave. Alan Lomax: Selected Writings, 1934-1997. Routledge, 2003.
Lomax, John Avery. Adventures of a Ballad Hunter: Sketches by Ken Chamberlain. Facs. of 1947 Ed. New York: Macmillan, 1947. (Includes an account of recording James Howard (Blind Jim Howard) in 1933, p. 126-127.)
Lornell, Kip. Virginia's Blues, Country & Gospel Records 1902-1943: An Annotated Discography. University Press of Kentucky, 1989. p. 107. (Contains discussion of a 78 rpm record for Victor by “Howard and Peak, The Blind Musicians,” one of whom might be James (Blind Jim) Howard. Recorded at Bristol, Tennessee, October 30, 1928.) 
Murphy, Carole. Aunt Molly Jackson: The Making of a Hero. Thesis (M.A.) Wesleyan University,1981.
Lomax, Alan, Woody Guthrie, and Pete Seeger. Hard Hitting Songs for Hard-hit People. Oak Publications, 1967. (Includes transcriptions of songs collected from Jim Garland, Sarah Ogan Gunning, and Aunt Molly Jackson.)

Lomax, Alan, Woody Guthrie, and Pete Seeger. Hard Hitting Songs for Hard-hit People. University of Nebraska Press, 2012.

Lomax, John A. and Lomax, Alan. American Ballads and Folk Songs. The MacMillan Company, 1934. (Includes songs collected from James (Blind Jim) Howard).

Lomax, John A. and Lomax, Alan. American Ballads and Folk Songs. Dover Publications, 1994.

Lomax, John A., Alan Lomax, and Ruth Crawford Seeger. Our Singing Country: A Second Volume of American Folk Songs and Ballads. The Macmillan Company, 1941.
(Includes transcriptions.)  

Currently as:
Lomax, John A., Alan Lomax, and Ruth Crawford Seeger. Our Singing Country: A Second Volume of American Folk Songs and Ballads. Dover, 2000.

Porterfield, Nolan. Last Cavalier: The Life and Times of John A. Lomax, 1867–1948. University of Illinois Press, 2001.
Romalis, Shelly. Pistol Packing Mama: Aunt Molly Jackson and the Politics of Folksong. University of Illinois Press. 1999. (Includes an anecdote on p. 131 that Leadbelly drove Aunt Molly Jackson and Mary Elizabeth Barnicle during a trip to Kentucky. Three recordings were made by Mary Elizabeth Barnicle of Leadbelly in Pineville, Kentucky in 1938.)

Adams, Carolyn Hazlett. “Aunt Molly Jackson: The Benefits and the Costs of Cussedness.” Appalachian Journal, Vol. 26, No. 3. Spring 1999, pp. 264-273.
Cohen, Norm. Western Folklore. Vol. 58, No. 1, Winter, 1999, pp. 90-93.
Portelli, Alessandro. The Journal of American History, Vol. 87, No. 2. Sep., 2000, pp. 716-717.
Yates, Michael. Folk Music Journal, Vol. 7, No. 5. 1999, pp. 661-664.

Szwed, John F. Alan Lomax: The Man Who Recorded the World. Viking Penguin, 2010. (Includes a discussion John and Alan Lomax recording James Howard (Blind Jim Howard), p. 50, and a discussion of Alan and Elizabeth Lomax's 1937 field recordings trip to Kentucky, pp. 11-115).    
Thomas, Jean. Ballad Makin’ in the Mountains of Kentucky. New York: Henry Holt. 1939.
Thomas, Jean. The Devil's Ditties: Being Stories of the Kentucky Mountain People Told by Jean Thomas. W. Wilbur Hatfield, 1931. (Includes information on Jilson Setters (J.W. Day).  
Thomas, Jean. The Singin' Fiddler of Lost Hope Hollow. E.P. Dutton, 1938. (The focus of the book is Jilson Setters (J.W. Day).   
Titon, Jeff Todd. Old-Time Kentucky Fiddle Tunes. University Press of Kentucky, 2001. Book and CD. (Includes general history of fiddling in Kentucky as well as biographies and tune transcriptions of several fiddlers in this collection.)

Wade, Stephen. The Beautiful Music All Around Us: Field Recordings and the American Experience. University of Illinois Press, 2012. (Includes extensive and in-depth chapters on three Kentucky musicians and one of their performances recorded by Alan Lomax: Pete Steele, William Hamilton (W.H.) Stepp, and Luther Strong.)

Review: Olson, Ted. The Old-Time Herald. Vol. 13, No. 11, 2014. p. 40.

Wolfe, Charles. Kentucky Country: Folk and Country Music of Kentucky. University Press of Kentucky, 1982. (Includes discussion of fieldwork conducted by Alan and Elizabeth Lomax and Mary Elizabeth Barnicle in Kentucky as well as some of the performers including Aunt Molly Jackson, Jim Howard, Justus Begley, and others.)