. . "The Boeing 720 was a four-engine narrow-body short- to medium-range passenger jet airliner. Developed by Boeing in the late 1950s from the Boeing 707, the 720 has a shorter fuselage and less range. The 720 first flew in November 1959 and the model entered service with launch customer United Airlines in July 1960.Two primary versions of the aircraft were built."@en . "154"^^ . "1958Z"^^ . . . . . "1967Z"^^ . "2010-09-29Z"^^ .