@misc{indiciae2cd07ed739a8,
  title = {Phelps' technical progress model generalized.},
  author = {G Steinmann and J L Simon},
  year = {1980},
  doi = {10.1016/0165-1765(80)90095-6},
  url = {https://pubmed.ncbi.nlm.nih.gov/12312014/},
  note = {Source identifier: 12312014}
}