Mehlhorn, Kurt Algorithms and Complexity, MPI for Informatics, Max Planck Society;
Preparata, Franco P. Max Planck Society;
Sarrafzadeh, Maji Max Planck Society;
https://rdcu.be/dwMqS (Publisher version)
Mehlhorn, K., Preparata, F. P., & Sarrafzadeh, M. (1986). Channel Routing in Knock-Knee Mode: Simplified Algorithms and Proofs. Algorithmica, 1(2), 213-221. doi:10.1007/BF01840443.