Liu, Jixue, and Millist Vincent. “Derivation of Incremental Equations for PNF Nested Relations”. Acta Cybernetica 16, no. 1 (January 1, 2003): 93-131. Accessed June 29, 2024. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3613.