Anthology

I'm reading a book that refers to Lorca's books of poems as "anthologies." Surely this is wrong. In English, anthology must refer to a selection from several poets, not one. (The book is written in English.). In Spanish, you can use antología for the work of a single poet, but in that case it must be poems selected from more than one book (a "selected poems."). Romancero gitano is not an "anthology" but a unitary collection, a poemario or book of poems.  The book is otherwise excellent in numerous ways, so that makes it all the more puzzling. I've never seen that in my life.