New York: Bureau of Publications Teachers College, Columbia University, 1939

National Council of Teachers of Mathematics, 1948

National Council of Teachers of Mathematics, 1948

National Council of Teachers of Mathematics, 1944

National Council of Teachers of Mathematics, 1944

National Council of Teachers of Mathematics, 1943

National Council of Teachers of Mathematics, 1943

National Council of Teachers of Mathematics, 1936

National Council of Teachers of Mathematics, 1936

National Council of Teachers of Mathematics, 1937

National Council of Teachers of Mathematics, 1937

National Council of Teachers of Mathematics, 1932

National Council of Teachers of Mathematics, 1932

National Council of Teachers of Mathematics, 1933

National Council of Teachers of Mathematics, 1933

National Council of Teachers of Mathematics, 1942

National Council of Teachers of Mathematics, 1942

JSTOR, 1940

Louisiana State University Press, 1940

JSTOR, 1940