That's supposed to be one of those Time-Life book series, "Legends of the Old West" or whatnot. (And that in the upper-left corner was my first attempt at a thought bubble. Yeah, I know... looks more pathetic than the Lone Ranger movie.)
TRANSCRIPTION COURTESY OF JOSEPH HOUK - (MG, off screen, reading a book) "Hmmm... That's weird. I've read this book from front to back, and I've never seen this section in it before... ["Crazy Cass Wilson" shoots "Big Joe" Burrows in Wichita?] Um, Cassie? Did you go back to the Old West recently?" (CW, off screen) "Yeah, just last week. Why you ask?"