TY - JOUR T1 - Convergence Analysis of the Multi-Frequency Approach around a Variable-Helix Instability Island JO - Procedia CIRP PY - 2019/07/10 AU - UreƱa L AU - Ozturk E AU - Sims N ED - DO - DOI: 10.1016/j.procir.2019.04.054 PB - Elsevier BV VL - 82 SP - 279 EP - 284 Y2 - 2024/12/25 ER -