L. ESSEN

The Units of Time and Length

L. ESSEN, 1957, Nature.

Atomic and Astronomical Time

L. ESSEN, J. V. L. PARRY, L. Essen, 1956, Nature.

Atomic Time and the Definition of the Second

L. ESSEN, 1956, Nature.

Comparison of C;æsium Frequency Standards of Different Construction

L. ESSEN, J. V. L. PARRY, J. H. HOLLOWAY, 1958, Nature.

Velocity of Light and of Radio Waves

L. ESSEN, L. Essen, K. Froome, 1971, Nature.