Vibrational resonance of ammonia molecule with doubly singular position-dependent mass Taiwo O. Roy-Layinde, Kehinde A. Omoteso, Babatunde A. Oyero, John A. Laoye and Uchechukwu E. Vincent Eur. Phys. J. B, 95 5 (2022) 80 Published online: 10 May 2022 DOI: 10.1140/epjb/s10051-022-00342-9