TY - ECHAP AU - I. Abella AU - A. Compaan AU - L. Lambert CY - Boston, MA DO - 10.1007/978-1-4613-4517-6_32 PB - Springer US PP - Boston, MA PY - 1974 SN - 978-1-4613-4519-0 SP - 457 EP - 467 TI - Observation of Superhyperfine Modulation and Quantum Beats in Photon-Echo Spectroscopy in Ruby ER -