@misc{indiciaeb88bf7ae1c5d,
  title = {Directional coupler for optical waveguides},
  author = {Schineller, E. R. and Wilmot, D. W.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700000367},
  note = {Source identifier: 19700000367}
}