For administrative queries, please contact M.M. Ravelli:

Visiting address:
Sterrenwachtlaan 11
2311 GW Leiden

Postal address:
Postbus 778
2300 AT Leiden

T: +31-(0)71-527-7748

E: gro.r1745499177ivnk@1745499177tcatn1745499177oc1745499177

To contact the Secretary of the Board of the Society, please send an email to gro.r1745499177ivnk@1745499177draob1745499177.