1. Hayakawa, M., K. Ohta, and S. Shimakura, Spaced direction finding of whistlers at low and equatorial latitudes and their propagation mechanism, J. Geophys. Res., 95: 15091 (1990).
2. Hayakawa, M., Direction finding of magnetospheric VLF/ELF emissions and their generation mechanism, in “Environmental and Space Electromagnetics”, Ed. by H. Kikuchi, Elsevier Pub. Comp., 155 (1991).
3. Bullough, K. and J. L. Sagredo, VLF goniometer observations at Halley Bay, Antarctica — I. The equipment and the measurement of signal bearing, Planet. Space Sci, 21: 899 (1973).
4. Tanaka, Y., VLF hiss observed at Syowa Station, Antarctica-I. Observation of VLF hiss, Proc. Res. Inst. Atmos. Nagoya Univ., 19: 33 (1972).
5. Cousins, M. D., Direction finding on whistlers and related VLF signals, Tech. Rept. SEL-72-013, Radioscience Lab., Stanford Univ. (1972).