Columbia University [Students talking.]

Columbia University [Students talking.]

Columbia University [Students talking in a stairway.]

Columbia University [Students talking in a stairway.]

Columbia University [Students talking.]

Columbia University [Professor talking with student.]

Columbia University [Professor talking to a student.]

Columbia University [Professor talking to a student.]

Columbia University [Students talking in a stairway.]

Columbia University [Students talking in a stairway.]

Columbia University [Students talking on a stairway.]

Columbia University [Professor talking to a student.]

Columbia University [Students talking in front of a mural.]

Columbia University [Students talking.]

Columbia University [Students talking.]

Columbia University [Two men talking.]

Columbia University [Two men talking.]

Columbia University [Two men talking.]

Columbia University [Two men talking.]

Columbia University [Three people talking.]