The author of “a poem for my librarian, mrs. long” most likely includes allusions to specific writers and books because she wants to

Emphasize the memorable role that books played in the speaker’s childhood.

Explanation:

In this poem, we learn about the author's childhood, and how deeply this was impacted by the books she read. The speaker reflects on Mrs. Long, and the role she played in these experiences, as Mrs. Long often helped the speaker find books that were not available in their "black" library. The speaker also talks about specific writers and books because she wants to emphasize the memorable role that books played in the speaker's life.