Collins, B. (1999). Questions about angels: Poems. University of Pittsburgh Press.
Cita Chicago Style (17a ed.)Collins, Billy. Questions About Angels: Poems. Pittsburgh: University of Pittsburgh Press, 1999.
Cita MLA (8a ed.)Collins, Billy. Questions About Angels: Poems. University of Pittsburgh Press, 1999.
Precaución: Estas citas no son 100% exactas.