sentences:  In 2011, they entered the Guinness World Records book as the pair of brothers with most world heavyweight title fight wins (30 at the time; 40 as of 2020).In the years following the retirement of undisputed heavyweight champion Lennox Lewis in 2004, the Klitschko brothers would eventually accumulate all four major world heavyweight titles.Known for their exceptionally large physiques and technical boxing styles, they each developed a style that utilized their athleticism and arm reach to break down opponents.