Holly Melgard's The Making of the Americans (Troll Thread, 2012), in which she deletes all repeated words from her source text (Gertrude Stein's The Making of Americans (1925)). Melgard's work is viewable online here.

Melgard explains, "Poems can exploit what it is in books that makes texts appear as “text”; how their distributions and multiple frameworks of production may play a material role in their composure, their poetics. Like Gertrude Stein’s The Making of Americans, which gets called 'unreadable' because it’s super 'repetitive'.... NOW 'there is no such thing as repetition' in The Making of Americans, because I deleted it." 

Read more of Melgard's ideas over at Elective Affinities, here. 

Plus, it's listed (along with some other interesting and conceptual work) as one of the top poetry books of 2012 by MS Magazine! (Thanks, Harriet, for the link.) 

We can also purchase a physical copy of Melgard's work here.