1. Study of a d.c. chopper as a sampled system;Bühler,1977
2. A general unified approach to modelling switching d.c.-to-d.c. converts in discontinuous conduction mode;Cuk,1977
3. Gemischte Nutz- und Widerstandsbremsung bei Untergrundbahnen;Eisele;ETZ-A,1969
4. Modelling linear systems for pulsewidth-modulated control;Friedland;IEEE Trans. on Automatic Control,1976