@article{CTT100631819,
  author = {Y. Narumi and S. Kimura and S. Hirai and K. Kindo and H. Schwenk and S. Schmidt and B. Wolf and B. Lüthi and T. Saito and M. Azuma and M. Takano},
  title = {High-Field Magnetization Measurements on Single Crystals of (VO)2P2O7},
  journal = {Physica B},
  year = 2001,
}

@article{CTT100631740,
  author = {H. Schwenk and D. König and S. Schmidt and M. Sieling and W. Palme and B. Lüthi and S. Zvyagin and R.S. Eccleston and M. Azuma and M. Takano},
  title = {Magnetic Resonances in Spin Ladder Systems (VO)2P2O7, SrCu2O3 and Sr2Cu3O5},
  journal = {Physica B},
  year = 1997,
}