(Altshiller-Court 1925, hlm. 74) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 73) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 73) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 73) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 74) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 73) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 79) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 79) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504
(Altshiller-Court 1925, hlm. 103–110) Altshiller-Court, Nathan (1925), College Geometry: An Introduction to the Modern Geometry of the Triangle and the Circle (edisi ke-2), New York: Barnes & Noble, LCCN52013504