@article{Smirnov:2016AX, author = "Smirnov, Vladimir and Henn, Johannes M. and Smirnov, Alexander and Steinhauser, Matthias", title = "{A planar four-loop form factor in QCD}", doi = "10.22323/1.260.0036", journal = "PoS", year = 2016, volume = "LL2016", pages = "036" }