World Scientific series in 20th century physicsPaper 4.1: N. Bloembergen and M.D. Levenson, “Observation of two-photon absorption without Doppler broadening on the 3S–5S transition in sodium vapor,” Phys. Rev. Lett. 32, 645–648, 1974.Published Sep 1, 1996• 2 citationsPublisherDOI10.1142/9789812795793_0041