To contact me just send an email to my firstname at ivarhagendoorn.com, that is:
ivar [add at] ivarhagendoorn.com
Before contacting me please bear in mind that I currently devote all (or most of) my spare time to my academic and creative pursuits. Consequently, it may take some time before I can reply to your request. I do my best to answer all email within two weeks of receipt (unless I'm travelling in which case it may take more time).
However.... don't let that keep you from contacting me! I'd love to hear from you.