Original sentence: From 1970 to 1972 he was an executive producer on ABC's The Dick Cavett Show and from 1982 to 1992 he was an executive producer of the NBC series Late Night With David Letterman
Edited sentence: From 1970 to 1972 he was an executive producer on ABC's The Dick Cavett Show and from 1982 to 1992 he was an executive producer of the long running NBC series Late Night With David Letterman