1. The Most Brilliant Little Victory: Nelson's Eastern Kentucky Campaign of 1861 by Marlitta H. Perkins (Lulu, 2014).
Local historian Perkins is a dedicated digger for source material pertaining to the Civil War in East Kentucky, some of which she posts to her blog. Though the campaign was summarized briefly but well in Donald Clark's 2011 Bull Nelson biography, Perkins's history of the Big Sandy Expedition is the first book length treatment.
2. Gateway to the Confederacy: New Perspectives on the Chickamauga and Chattanooga Campaigns, 1862-1863 edited by Evan C. Jones and Wiley Sword (LSU Pr, 2014).
This looks to be a fascinating group of articles. I like that it recognizes the campaign for Chattanooga as beginning in 1862 (there is a chapter covering Buell's advance) and many of the pieces are driven by subject themes differing from those present in other recently published Chickamauga-Chattanooga books and essay compilations.