Mitragotri's key inventions include technologies that make it possible to deliver medicines into the body without using needles.
In two key inventions Swindin solved both of these for many situations.
However, it was only after three key inventions were in place that the fountain pen became a widely popular writing instrument.
These use two key inventions that were important to the early commercial gas engines (which do not appear until over 20 years later).
This was a key evolutionary 'invention', which allowed the amniotes to invade the land.
Two key inventions led to the development of magnetic core memory in 1951.
Kruesi was also involved in many of Edison's key inventions.
The key invention here was a parochial school system that had no parallel elsewhere in the world.
Without his two key inventions, sound recording and motion picture film, the whole celebrity business would be bankrupt.
Clarke defined how to make a great discovery or create a key invention.