Jensen, J. M. (2010) “Output factors for squared, rectangular and elongated photon fi elds of linear accelerators: A supplement to Stirling’ formula”, Journal of Thai Association of Radiation Oncology, 16(1), pp. 42–49. available at: https://he01.tci-thaijo.org/index.php/jtaro/article/view/203515 (accessed: 15 September 2026).