Two-photon spectroscopy of neutral barium: Observations of the highly excited even levels and theoretical analysis of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>J</mml:mi><mml:mo>=</mml:mo><mml:mn>0</mml:mn><mml:mn/></mml:math>spectrumM Aymar, C. Morillon, P. Camus et al.|Physical Review A|1978Cited by 113