L Essen

A precision frequency-meter of range 0 to 2000 Mc./sec.

L Essen, L. Essen, 1940 .

A time dilatation experiment based on the Mössbauer effect

L Essen, L. Essen, 1965 .

A new form of frequency and time standard

L Essen, L. Essen, 1938 .