A. Dardis and C. R. Rosenstiel, "The four least solutions in distinct positive integers of the Diophantine equation s = x3 + y3 = z3 + w3 = u3 + v3 = m3 + n3", Bull.
A. Dardis and C. R. Rosenstiel, "The four least solutions in distinct positive integers of the Diophantine equations = x3 + y3 = z3 + w3 = u3 + v3 = m3 + n3", "Bull.