George, K. O., & Tilley, D. (2002). Swimming upstream: Middle school poems. Houghton Mifflin Harcourt.
Cita Chicago Style (17a ed.)George, Kristine O'Connell, y Debbie Tilley. Swimming Upstream: Middle School Poems. Boston: Houghton Mifflin Harcourt, 2002.
Cita MLA (8a ed.)George, Kristine O'Connell, y Debbie Tilley. Swimming Upstream: Middle School Poems. Houghton Mifflin Harcourt, 2002.
Precaución: Estas citas no son 100% exactas.