Adrian Keller wrote a 267 page book 'Elvis Before Graceland', this is what Amazon says about it:
Before Elvis made it on the regional scene as an established musician, he worked at Crown Electric in Memphis as a truck driver and do-all boy. Elvis and the owner of Crown Electric, James Tipler, remained close friends over the years. Tipler stayed in business until 1990 and, in 1986 he hired a young European immigrant in pretty much the same position he once hired Elvis. With time, Tipler and the young man became close friends. Tipler shared with the young immigrant his memories of the mid-fifties, Elvis' work habits, documents, and memorabilia unique to a period of Elvis' life, very little of which has been known until now. "Elvis Before Graceland" is Elvis' unique story at Crown Electric and a treasure trove for all interested fans. With over forty never-released photos, documents associated directly with Elvis and with his early years.
Source: Email / Updated: Apr 10, 2018