The principle that states that two different species cannot occupy the same niche in a given habitat is called what

The principle that states that two different species cannot occupy the same niche in a given habitat is called principle of competitive exclusion.

It is also called as Gauses's principle or Grinnell's axiom (after G. F Gause, a soviet biologist and J. Grinnell, an american naturalist, who first clearly established it).