1. Ericsson, U., FOA 4 Report, C 4400–20 (Hagfors Observatory, 1969).
2. Slunga, R., FOA report (in the press).
3. NOAA, Preliminary Epicentre Determination of Epicentres, No. 66–69, and No. 57–73.
4. Davies, D., Some Remarks on Short period Discrimination, Woods Hole Conference in Seismic Discrimination (Advanced Research Projects Agency, 1970).
5. Israelson, H., Seismic Identification Using Short period Hagfors Data, in Proc. Seminar on Seismology and Seismic Arrays (Oslo, 1972).