[2] Belobrov P.K.:
The Čebyšev point of a system of sets. Izv. Vysš. Učebn. Zaved. Matematika 55 (1966), 18–24.
MR 0208332 |
Zbl 0192.22501
[3] Bestvina M.:
$\mathbb R$-trees in Topology, Geometry, and Group Theory. Handbook of Geometric Topology, 55–91, North-Holland, Amsterdam, 2002.
MR 1886668
[5] Borsuk K.:
On the third symmetric potency of the circumference. Fund. Math. 36 (1949), 236–244.
MR 0035987 |
Zbl 0039.19301
[6] Borovikova M., Ibragimov Z.:
The third symmetric product of $ \mathbb R$. Comput. Methods Funct. Theory 9 (2009), 255–268.
DOI 10.1007/BF03321726 |
MR 2478275
[7] Borovikova M., Ibragimov Z., Yousefi H.:
Symmetric products of the real line. J. Anal. 18 (2010), 53–67.
MR 2850235 |
Zbl 1239.30030
[9] Bridson M.R., Haefliger A.:
Metric spaces of non-positive curvature. Grundlehren der Mathematischen Wissenschaften, 319, Springer, Berlin, 1999.
MR 1744486 |
Zbl 0988.53001
[12] Illanes A.:
Nadler S.B., Jr. {\it Hyperspaces}, Marcel Dekker, New York, 1999.
MR 1670250
[13] Ivanshin P.N., Sosov E.N.:
Local Lipschitz property for the Chebyshev center mapping over N-nets. Mat. Vesnik 60 (2008), 9–22.
MR 2403268 |
Zbl 1199.54169
[15] Molski R.:
On symmetric product. Fund. Math. 44 (1957), 165–170.
MR 0092953
[16] Morton H.R.:
Symmetric product of the circle. Proc. Cambridge Philos. Soc. 63 (1967), 349–352.
MR 0210096
[17] Valentine F.A.:
Convex Sets. McGraw-Hill Series in Higher Mathematics, McGraw-Hill Book Co., New York-Toronto-London, 1964.
MR 0170264 |
Zbl 0333.52001
[18] Wu W.:
Note sur les produits essentiels symétriques des espaces topologiques. C.R. Acad. Sci. Paris 224 (1947), 1139–1141.
MR 0019914