Brandal, Petter, Bodil Bjerkehagen, Øyvind S. Bruland, Sigmund Skjeldal, Trond V. Bogsrud, and Kirsten S. Hall. 2009. “Synchronous and Metachronous Skeletal Osteosarcomas: The Norwegian Radium Hospital Experience”. Acta Oncologica 48 (8):1165-72. https://doi.org/10.3109/02841860903032809.