Talha, M. S., Waseem, M., Ali, Z., Fatima, N., Shah, K., & Abdeljawad, T. (2026). A Unified Nonlinear Mathematical Model Based on Smoking-Vaping Dynamics with Spectral Graph Analysis and Simulation. Contemporary Mathematics, 7(3), 3705–3737. https://doi.org/10.37256/cm.7320269704