Citation, Documentation of Sources

Q. Please help. I need to cite a few lines from a poem, but there are no page numbers in the book of poems. Do I make page numbers up? Do I use poem 1, poem 2? My cites are to be author/date style. For example, after my quote I need to reference it, as in (Grimes 1999, ???). No page numbers!

A. If you’ve already mentioned the poem’s title or number in the text, you can write (Grimes 1999, n.p.), which indicates that there are no page numbers. If you haven’t mentioned a title or number, you can add it to the citation: (Grimes 1999, “Something Will Happen”). “N.p.” is optional in any case.