APA (7th ed.) Citation

Obama, B., & Long, L. (2010). Of thee I sing: A letter to my daughters. Alfred A. Knopf.

Chicago Style (17th ed.) Citation

Obama, Barack, and Loren Long. Of Thee I Sing: A Letter to My Daughters. New York: Alfred A. Knopf, 2010.

MLA (8th ed.) Citation

Obama, Barack, and Loren Long. Of Thee I Sing: A Letter to My Daughters. Alfred A. Knopf, 2010.

Warning: These citations may not always be 100% accurate.