Wang, Xue Ping. “Gevrey-Type Resolvent Estimates at the Threshold for a Class of Non-Selfadjoint Schrödinger Operators”. Bruno Pini Mathematical Analysis Seminar 6, no. 1 (January 1, 2015): 69–85. Accessed April 3, 2025. https://mathematicalanalysis.unibo.it/article/view/5891.