Steve McQueen’s brand of cool has no expiration date. Thirty years after the star’s death, McQueen’s steely charisma still holds our attention.While there are numerous hardbound tributes to the actor, Marshall Terrill’s “Steve McQueen, A Tribute to the King of Cool,” and “Steve McQueen, The Last Mile,” by the actor’s widow, Barbara McQueen (co-written with Terrill), stand as an essential and complimentary pair.The sprawling “King of Cool” tells McQueen’s story via some 200 first-person accounts from friends, family, biker pals and movie stars. Arranged in roughly chronological order, the varied perspectives examine McQueen from every conceivable angle. The result is a 360-degree image of a complex subject that a traditional biography could not deliver.The volume’s exhaustive photography paints a portrait of enigmatic cool in mosaic-there is the elegant, Persol’d “Thomas Crown Affair” McQueen beside the bearded, wild-eyed beer drinker in grimy Levi’s. Throughout the book’s 381 pages you see a man entirely comfortable in his own skin.“The Last Mile” offers a more personal perspective from McQueen’s widow, chronicling their relationship during the last years of the actor’s life. As with “King of Cool,” the book’s comprehensive photography is worth the price of admission alone.Throughout, Barbara McQueen offers intimate recollections of the couple’s time away from the spotlight, along with a few surprising revelations.