Amit Kumar, Dharmendra Kumar, Ashwani Saharan (2026). Advance Periodic Waves and Closed-Form Invariant Solutions for $$(2 + 1)$$-Dimensional Hyperbolic Nonlinear Schrödinger (HNLS) Equation via Two Efficient Mathematical Approaches. Electronic ISSN, 65(4). https://doi.org/10.1007/s10773-026-06313-5