Schlegel from Hagen in Westfalen, « On the problem of the minimum sum of the distances of a point from given points », Bulletin of the American Mathematical Society, vol. 1, no 2, , p. 33–52 (DOI10.1090/s0002-9904-1894-00242-0, MR1557288)
Schlegel from Hagen in Westfalen, « On the problem of the minimum sum of the distances of a point from given points », Bulletin of the American Mathematical Society, vol. 1, no 2, , p. 33–52 (DOI10.1090/s0002-9904-1894-00242-0, MR1557288)