1. Lorentz's pendulum problem;Littlewood;Ann. Phys.,1963
2. Adiabatic variation. I. Exponential property for the simple oscillator;Meyer;Z. Angew. Math. Phys.,1973
3. Exponential asymptotics;Meyer;SIAM Rev.,1980
4. Asymptotics and Special Functions;Olver,1974
5. Adiabatic invariance of a simple oscillator;Wasow;SIAM J. Math. Anal.,1973