"Stephenson link gear" . "reversing lever" . . "Stephenson valve gear" . "Stephenson type" . "Allan straight link valve gear" . . "variable timing valve" . "Stephenson's" . "Stephenson link motion" . "Stephenson" . . "Stephenson-link motion" . "Allan valve gear" . "Stephenson valve gear#Allan straight link valve gear" . . "Stephenson_valve_gear#Gooch_valve_gear" . "Stephenson link valve gear" . "Stephenson\u2019s Link" . . "Allan Straight Link" . "Stephenson valve gear" . "Stephenson valve gear#Allan gear" . "new form" . . "Stephenson Link" . "Allan" . "Stephenson link-motion" . "Gooch valve" . . "Stephenson's link motion" . "Stephenson motion" . . . . "Stephenson Link valve gear" . . . "Stephenson's valve gear" . . "outside Stephenson valve gear" . "Stephenson pattern" . "Allan straight link" . . "Stephenson link" . . . "Stephenson design" . .