Columbia University [Professor with students in an office.]
Columbia University [Student with professor in an office.]
Columbia University [Professor with student in an office.]
Columbia University [Students and professor in an office.]
Columbia University [Students in a professor's office.]
Columbia University [Professor with a student.]
Columbia University [Students rehearsing an opera.]
Columbia University [Professor talking with student.]
Columbia University [In one year, Columbia professors wrote this many books.]
Columbia University [Students studying.]