Columbia subject headings:
Degrees, Academic.
Science--Study and teaching (Higher)
Harvard subject headings:
Degrees, Academic.
Doctor of philosophy degree.
Engineering--Study and teaching (Higher)--United States
Science--Study and teaching (Higher)
Science--Study and teaching (Higher)--United States
Princeton subject headings:
Doctor of philosophy degree.
Engineering--Study and teaching (Higher)--United States.
Science--Study and teaching (Higher)--United States.