ULTRASONIC PHONON VELOCITIES IN Cdl-xMnxTe BETWEEN 1.5 AND 96 K : ANOMALIES NEAR THE MAGNETIC TRANSITION A.Y. Wu and R.J. Sladek J. Phys. Colloques, 42 C6 (1981) C6-646-C6-648 DOI: 10.1051/jphyscol:19816188