CARRIER-CONCENTATION-DEPENDENT ELECTRON LO-PHONON COUPLING OBSERVED IN GAAS-(GA,AL)AS HETEROJUNCTIONS BY RESONANT-POLARON CYCLOTRON-RESONANCE - Langerak, C; Singleton, J; Vanderwel, P; Perenboom, J; Barnes, D; Nicholas, R; Hopkins, M; Foxon, C (1988)