TY - JOUR
AU - V. Čermák
CY - Boulder
DA - 1966-01
M1 - 63
PP - Boulder
PY - 1966
SP - 1
EP - 52
TI - I. Individual Efficiency Curves for the Excitation of 23S and 21S States of Helium by Electron Impact  II. Retarding Potential Measurement of the Kinetic Energy of Electrons Released in Penning Ionization
SN - 63
ER -