Distance-regular Graphs the Distance Matrix of which has Only One Positive Eigenvalue

@article{Koolen1994DistanceregularGT,
  title={Distance-regular Graphs the Distance Matrix of which has Only One Positive Eigenvalue},
  author={Jacobus H. Koolen and Sergey V. Shpectorov},
  journal={Eur. J. Comb.},
  year={1994},
  volume={15},
  pages={269-275}
}