Columbia University [Student carrying a stack of books down stairs.]

Columbia University [Student carrying a stack of books down stairs.]

Columbia University [Student carrying a stack of books down stairs.]

Columbia University [Women carrying a stack of books down a flight of stairs.]

Columbia University [Women carrying a stack of books down a flight of stairs.]

Columbia University [Woman carrying a large stack of books down stairs.]

Columbia University [Man carrying a box down stairs.]

Columbia University [Woman with a large stack of books walking down a flight of stairs.]

Columbia University [Woman with a large stack of books walking down a flight of stairs.]

Columbia University [Woman with a large stack of books walking down a flight of stairs.]

Columbia University [Woman with a large stack of books walking down a flight of stairs.]

Columbia University [Women carrying large stack of books down stairs.]

Columbia University [Group of students.]

Columbia University [Group of students.]

Columbia University [Group of students.]

Columbia University [Group of students.]

Columbia University [Group of students.]

Columbia University [Group of students.]

Columbia University [Group of students.]

Columbia University [Group of students.]