@misc{debruin2001var21,
   author = {{de Bruin}, H. and Proper, Henderik A.},
   month = {November},
   title = {{VAR21} -- {De} Business Case Voor Architectuur},
   url = {http://www.niii.kun.nl/is/Docs/Presentation:01:DeBruin:VAR21.pdf},
   urldate = {2001-12-20},
   year = {2001},
}