@unpublished{AHM-DTD,
  author	= {Hardman, L. and van Ossenbruggen, J. and Bulterman, D. C. A.},
  note		= {VU/CWI},
  title		= {A HyTime-Compliant Interchange Format for CMIF Hypermedia Documents},
  year		= {1995},
  month		= aug
}