From DiMag & Mick: Sibling Rivals, Yankee Blood Brothers (Lyons Press) available at Amazon.com.
1. Both Joe DiMaggio and Mickey Mantle were golfers who enjoyed being on the links — so long as someone else was picking up the green fees, such as sponsors of celebrity tournaments who often sought them out, paid then well and stocked them with apparel and equipment, including expensive sets of golf clubs. DiMaggio’s garage in San Francisco was full of top name sets of clubs given to him but which he had never played with and sometimes gave to friends as birthday and Christmas presents.
2.While playing with the Yankees, both Joe and Mickey regularly ate at the Stage Delicatessen on 54th Street in 
Manhattan where they became good friends of owners Max and Hymie Asnas and their families. The Asnas brothers often made them special meals that were not on their menu. In Mick’s rookie season, they even housed Mantle and some teammates in an apartment above the deli.
3.Both Joe and Mickey were cheap when it came to spending money on the women they married. The four and one-half carat, emerald cut diamond engagement ring that Joe gave to his first wife Dorothy Arnold, the actress he married at San Francisco’s St. Peter and Paul Church on Nov. 19, 1939, was paid for by Newark crime boss Ruggiero “Richie the Boot” Bojardo. Merlyn Mantle’s wedding ring for her 1951 marriage to Mick was bought by Theodore Mantle, Mickey’s half-brother, who had used most of his army discharge pay to help pay for it.
4.Both Joe and Mickey had their names carried on by sons who led tragic lives. Joe DiMaggio Jr., died Aug. 6, 1999, at the age of 57, apparently of natural causes — five months after his father’s own death. He was estranged from his father. When his father died, Joe Jr. was living in a trailer and working in a junkyard. Mickey Mantle Jr., struggled against the alcoholism that engulfed his father and other family members and died Dec. 20, 2000, at age 47, from complications of cancer.
5.Both DiMaggio and Mantle turn up in files of the FBI. According to one FBI document: “Our microphone surveillance covering Rhode Island hoodlum, Raymond Patriarca has revealed that Patriarca has unidentified connections in the Rhode Island State Police; that he is considering putting Frank Sinatra and Joe DiMaggio on the Board of Directors of Hancock Race Track, Berkshire County, Massachusetts, to lend ‘class’ to the race track.” In Mantle’s dossier, on document links Mickey to illegal prostitution and gambling operations and reports that” in the course of an interstate gambling investigation — which originated in Oklahoma, Mantle’s birthplace — the athlete’s Dallas phone number surfaced.” An FBI redaction mark hides what Mantle supposedly bet.