Yes, Bob DeArment wrote a number of excellent books focused on the history of the Old West. Possibly his most important is his biography of Bat Masterson, titled, Bat Masterson, oddly enough. It is generally considered to be the standard Masterson biography. Being an honest historian, DeArment corrected some of his statements about Masterson from that book when he wrote about Masterson's later years in Gunfighter in Gotham. His later research changed a few previously accepted statements about Bat's life. I very much appreciated Bob's three-volume Deadly Dozen series about "forgotten gunfighters" and his two-volume Man-Hunters of the Old West about... well, man-hunters. Any of these books can be found wherever you find books (Amazon, of course, but I tend to watch for good used copies on eBay, ABE Books, Thrift Books, etc.).
I like Charlie Siringo's books, but they have to be read a little differently. He was not a historian, but he was a participant in many exciting events. His books are mostly memoirs and, like most of us, his memories of events puts himself in the best light. He also had a couple of axes to grind, which comes out in his writing. I'd probably recommend starting off with A Cowboy Detective.
Hopefully that helps.
Griff