@misc{indiciae9042c5f2f733,
  title = {Electronic filters, signal conversion apparatus, hearing aids and methods},
  author = {Morley, Jr., Robert E. and Engebretson, A. Maynard and Engel, George L. and Sullivan, Thomas J.},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/20080004803},
  note = {Source identifier: 20080004803}
}