1. Braak, J. W. G. ter, P. Crezée, W. A. M. Grandia andM. de Vlieger, The Significance of some reflections in ?Echo-encephalography?. Acta neurochir., Wien,9 (1961), 382?397.
2. Gordon, D. M., Echoencéphalographie. Rev. neurol., Paris,99 (1958), 652?653.
3. Gordon, D. M., Echo-Encephalography. Ultrasonic Rays in Diagnostic Radiology. Brit. Med. J.5136 (1959), 1500?1504.
4. Jefferson, A., Some experiences with Echo-Encephalography. J. Neurol., London,22 (1959), 83 to 84.
5. Jeppsson, S., Echo-Encephalography. III. Further studies on the sources of the Midline Echo and a Clinical Evaluation. Acta chir. Scand.119 (1960), 455 to 462.