The magnum opus of the history of the Union of Brest is Fr. Borys Gudziak’s book Crisis and Reform. This is an expansion of his excellent doctoral dissertation from Harvard.
Another good book is Metropolitan Andrew written by Cyril Korolevsky and available in an English translation from Eastern Christian Publications. A more recent account of the Ukrainian Greek Catholic Church in the underground is Passion and Resurrection by Serge Keleher and Confessor between East and West, a wonderful biography of Patriarch Josyp by Jaroslav Pelikan.
FDRLB