You can reach the Stieltjes Institute by:

Postal Mail: Thomas Stieltjes Institute for Mathematics
c/o Snellius
Leiden University
P.O. Box 9512
2300 RA Leiden
The Netherlands

Telephone or Fax:
Phone: +31 71 527 7042
Fax: +31 71 527 7101

Electronic Mail:
mailto: stieltjes@math.leidenuniv.nl