On the divergence of perturbation theory for anharmonic oscillators

Multiple well anharmonic oscillators and perturbation theory

Quantum-mechanical oscillator with arbitrary anharmonicity: 1/N Expansion and perturbation theory

Dynamical Mean-Field Approach to Anharmonic Oscillators under Time-Dependent Perturbations

Second quantisation, variational principle and perturbation series for the anharmonic oscillator

Optimized perturbation method for the propagation in the anharmonic oscillator potential

Matrix moment methods in perturbation theory, boson quantum field models, and anharmonic oscillators