Perry, L. S., & Caswell Perry, E. (1981). My friend Carl Sandburg: The biography of a friendship. Scarecrow Pr..
Lua i Stíl Chicago (17ú heag.)Perry, Lilla S., agus E. Caswell Perry. My Friend Carl Sandburg: The Biography of a Friendship. Metuchen, N.J. ; London: Scarecrow Pr., 1981.
Lua MLA (8ú heag.)Perry, Lilla S., agus E. Caswell Perry. My Friend Carl Sandburg: The Biography of a Friendship. Scarecrow Pr., 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.