classic papers of the week -- 90

The Maser-New Type of Microwave Amplifier, Frequency Standard, and Spectrometer

• Gordon, J. P.; Zeiger, H. J.; Townes, C. H. (Columbia University, New York, NY)

Anomaly Cancellation in Supersymmetric D=10 Gauge Theory and Superstring Theory

• Michael B. Green (Queen Mary College, University of London & California Institute of Technology, Pasadena, CA) , John H. Schwarz (California Institute of Technology, Pasadena, CA)

The morphology of extragalactic radio sources of high and low luminosity

• Fanaroff, B. L.; Riley, J. M.