American Poetry: The Twentieth Century. New York: Literary Classics of the United States, 2000. Print.
Carruth, Hayden. "Robert Frost." Parnassus: Poetry in Review (Spring-Summer 1975): 35-41. Rpt. in Contemporary Literary Criticism. Ed. xxxxxDedria Bryfonski. Vol. 10. Detroit: Gale Research, 1979. Literature Resource Center. Web. 13 Mar. 2013.
Greiner, Donald J. "Robert Frost." American Poets, 1880-1945: Third Series. Ed. Peter Quartermain. Detroit: Gale Research, 1987. Dictionary of xxxxxLiterary Biography Vol. 54. Literature Resource Center. Web. 13 Mar. 2013.
Johnson, Robert K. "Robert Frost: Overview." Reference Guide to American Literature. Ed. Jim Kamp. 3rd ed. Detroit: St. James Press, 1994. xxxxxLiterature Resource Center. Web. 13 Mar. 2013.
"Robert Lee Frost." Encyclopedia of World Biography. Detroit: Gale, 1998. Biography In Context. Web. 8 Mar. 2013.
Carruth, Hayden. "Robert Frost." Parnassus: Poetry in Review (Spring-Summer 1975): 35-41. Rpt. in Contemporary Literary Criticism. Ed. xxxxxDedria Bryfonski. Vol. 10. Detroit: Gale Research, 1979. Literature Resource Center. Web. 13 Mar. 2013.
Greiner, Donald J. "Robert Frost." American Poets, 1880-1945: Third Series. Ed. Peter Quartermain. Detroit: Gale Research, 1987. Dictionary of xxxxxLiterary Biography Vol. 54. Literature Resource Center. Web. 13 Mar. 2013.
Johnson, Robert K. "Robert Frost: Overview." Reference Guide to American Literature. Ed. Jim Kamp. 3rd ed. Detroit: St. James Press, 1994. xxxxxLiterature Resource Center. Web. 13 Mar. 2013.
"Robert Lee Frost." Encyclopedia of World Biography. Detroit: Gale, 1998. Biography In Context. Web. 8 Mar. 2013.