@inproceedings{Seidl03Numerical,
  author = {Helmut Seidl and Thomas Schwentick and Anca Muscholl},
  title = {Numerical document queries},
  booktitle = {Principles of Database Systems},
  month = {June},
  year = 2003,
  pages = {155-166},
  publisher = {ACM},
  address = {San Diego, CA, USA},
}