accident triangle theory
... that the 1931 accident triangle theory proposed a link between the number of minor accidents and those that led to serious injury?
... that the 1931 <b id="mwBPc"><a href="./Accident_triangle" id="mwBPg" rel="mw:WikiLink" title="Accident triangle">accident triangle theory</a></b> proposed a link between the number of minor accidents and those that led to serious injury?