TY  - GEN
AU  - W B Chadwick
C2  - , National Institute of Standards and Technology, Gaithersburg, MD
DA  - 1961-01-01 05:01:00
DO  - https://doi.org/10.6028/NBS.TN.117
LA  - en
PB  - , National Institute of Standards and Technology, Gaithersburg, MD
PY  - 1961
TI  - Variations in frequency of occurrence of sporadic E, 1949-1959:
ER  -