Assertion: traditional trampoline | /r/HasProperty | designed by george nissen
Facets:
value: in the 1930s
type: TEMPORAL
Source sentences:
text: After careful analysis of worldwide trampoline data in 1992, Dr Keith Vivian Alexander of Canterbury University, Christchurch, New Zealand, revealed that there were three major impact zones to a traditional trampoline designed by George Nissen in the 1930s; these impact zones would need to be engineered out in order to build the safest trampoline: