@book{
  internationaliaea,
  title={Radioisotope Teletherapy Equipment},
  series={Technical Directories},
  year={},
  isbn={92-0-112059-1},
  url={https://www.iaea.org/publications/1475/radioisotope-teletherapy-equipment},
  publisher={INTERNATIONAL ATOMIC ENERGY AGENCY},
  address={Vienna}
}