Family Chronicle. Dating Old Photographs 1840-1929, and, More Dating Old Photographs 1840-1929. Toronto, Canada: Moorshead Magazines, 2004. (TE)
These books help identify the date of old family photographs from printing techniques, hair and clothing styles, etc. with many examples.
Taylor, Maureen A. Uncovering Your Ancestry through Family Photographs. 2nd ed. Cincinnati: Family Tree Books, 2005. (TE)