@inbook{10031,
  author = {I. Abella and A. Compaan and L. Lambert},
  title = {Observation of Superhyperfine Modulation and Quantum Beats in Photon-Echo Spectroscopy in Ruby},
  year = {1974},
  pages = {457-467},
  publisher = {Springer US},
  address = {Boston, MA},
  isbn = {978-1-4613-4519-0},
  doi = {10.1007/978-1-4613-4517-6_32},
}