@misc{indiciae3d7e6ce38c86,
  title = {Orthogonality, positive operators, and the frequency-power formulas},
  author = {Skoog, R. A. and Willems, J. C.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19710064264},
  note = {Source identifier: 19710064264}
}