sleep medicine
... that eighteen years ago, medical schools in the US "covered" sleep medicine in an average total teaching time of just two hours?
... that eighteen years ago, <a href="./Medical_school" id="mwDi0" rel="mw:WikiLink" title="Medical school">medical schools</a> in the US "covered" <b id="mwDi4"><a href="./Sleep_medicine" id="mwDi8" rel="mw:WikiLink" title="Sleep medicine">sleep medicine</a></b> in an average total teaching time of just two hours?