by United States. Bureau of Mines. Technical Library, Pittsburgh

1968

by Carnegie Library of Pittsburgh

1921

by Pittsburgh, Pa. Carnegie Free Library of Alleghany

1913

by Carnegie Library of Pittsburgh

1914

by Carnegie Library of Pittsburgh

1913

by Carnegie Library of Pittsburgh

1914

by Pittsburgh. First National Bank

1919

by Pittsburgh (Pa.). First National Bank

1919

by University of Pittsburgh

1924

by Carnegie Library of Pittsburgh

1929

by Engineers' Society of Western Pennsylvania, Pittsburgh

1929

by University of Pittsburgh. Graduate School

1927