@misc{indiciae9f830adb85a2,
  title = {Long-term temporal variability of Cygnus X-2},
  author = {Vrtilek, S. D. and Swank, J. H. and Kelley, R. L. and Kahn, S. M.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19880052973},
  note = {Source identifier: 19880052973}
}