Jun Ik Lee Yun-Ho Kim Jongrak Lee Existence of Small-Energy Solutions to Nonlocal Schrödinger-Type Equations for Integrodifferential Operators in ℝN. 5 2020 12 Symmetry 1 https://doi.org/10.3390/sym12010005 db/journals/symmetry/symmetry12.html#LeeKL20