1990 · Boris Andreevich Filippov · The University of North Carolina at Chapel Hill Digital Collections (The University of North Carolina at Chapel Hill)
1974 · Boris Andreevich Filippov · The University of North Carolina at Chapel Hill Digital Collections (The University of North Carolina at Chapel Hill)
1961 · Boris Andreevich Filippov · The University of North Carolina at Chapel Hill Digital Collections (The University of North Carolina at Chapel Hill)
1957 · Boris Andreevich Filippov · The University of North Carolina at Chapel Hill Digital Collections (The University of North Carolina at Chapel Hill)