@misc{indiciae4f8422a62584,
  title = {Necessary and sufficient conditions for optimality for singular control problems - A limit approach},
  author = {Jacobson, D. H. and Speyer, J. L.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700016063},
  note = {Source identifier: 19700016063}
}