A. Billionnet and M. Costa, Solving the uncapacited plant location problem on trees, Discrete Applied Mathematics, vol.49, issue.1-3, pp.51-59, 1994.
DOI : 10.1016/0166-218X(94)90200-3
URL : https://hal.archives-ouvertes.fr/hal-01124502

J. Byrka, An optimal bifactor approximation algorithm for the metric uncapacitated facility location problem, Proc. 10th Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX), pp.29-43, 2007.

M. Charikar and S. Guha, Improved combinatorial algorithms for the facility location and k-median problems, 40th Annual Symposium on Foundations of Computer Science (Cat. No.99CB37039), pp.803-824, 2005.
DOI : 10.1109/SFFCS.1999.814609

F. A. Chudak and D. B. Shmoys, Improved Approximation Algorithms for the Uncapacitated Facility Location Problem, SIAM Journal on Computing, vol.33, issue.1, pp.1-25, 2003.
DOI : 10.1137/S0097539703405754

K. Dhamdhere, V. Goyal, R. Ravi, and M. Singh, How to Pay, Come What May: Approximation Algorithms for Demand-Robust Covering Problems, 46th Annual IEEE Symposium on Foundations of Computer Science (FOCS'05), pp.367-378, 2005.
DOI : 10.1109/SFCS.2005.42

U. Feige, K. Jain, M. Mahdian, and V. S. Mirrokni, Robust Combinatorial Optimization with Exponential Scenarios, Proc. 12th Int. Conf. on Integer Programming and Combinatorial Optimization (IPCO), pp.439-453, 2007.
DOI : 10.1007/978-3-540-72792-7_33

S. Guha and S. Khuller, Greedy Strikes Back: Improved Facility Location Algorithms, Journal of Algorithms, vol.31, issue.1, pp.228-248, 1999.
DOI : 10.1006/jagm.1998.0993
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.220.384

S. Guha, A. Meyerson, and K. Munagala, A constant factor approximation algorithm for the fault-tolerant facility location problem, Journal of Algorithms, vol.48, issue.2, pp.429-440, 2003.
DOI : 10.1016/S0196-6774(03)00056-7

K. Jain, M. Mahdian, and A. Saberi, A new greedy approach for facility location problems, Proceedings of the thiry-fourth annual ACM symposium on Theory of computing , STOC '02, pp.731-740, 2002.
DOI : 10.1145/509907.510012

K. Jain and V. Vazirani, An Approximation Algorithm for the Fault Tolerant Metric Facility Location Problem, Proc. APPROX, pp.177-183, 2000.
DOI : 10.1007/s00453-003-1070-1

S. Khuller, R. Pless, and Y. Sussmann, Fault tolerant k-center problems, Theoret. Comput. Sci, vol.242, pp.12-237, 2000.
DOI : 10.1007/3-540-62592-5_59
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.24.7152

M. Mahdian, Y. Ye, and J. Zhang, Approximation Algorithms for Metric Facility Location Problems, SIAM Journal on Computing, vol.36, issue.2, pp.411-432, 2006.
DOI : 10.1137/S0097539703435716
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.9.8662

D. B. Shmoys, Approximation Algorithms for Facility Location Problems, Proc. 3rd Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX), pp.265-274, 1913.
DOI : 10.1007/3-540-44436-X_4
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.105.9226

C. Swamy and D. Shmoys, Fault-tolerant facility location, Proc. 14th ACM-SIAM SODA, pp.735-736, 2003.
DOI : 10.1145/1383369.1383382
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.124.6713

L. A. Wolsey, An analysis of the greedy algorithm for the submodular set covering problem, Combinatorica, vol.7, issue.3, pp.385-393, 1982.
DOI : 10.1007/BF02579435