@article{Boels:20167u,
  author = "Boels, Rutger  and  Kniehl, Bernd  and  Yang, Gang",
  title = "{On a four loop form factor in N=4}",
  doi = "10.22323/1.260.0039",
  journal = "PoS",
  year = 2016,
  volume = "LL2016",
  pages = "039"
}