Francis, G. E., Mulligan, W., Wormall, A., & Hevesy, G. (1959). Isotopic tracers: A theoretical and practical manual for biological students and research workers (2nd ed.). London: University of London. The Athlone Press.

Francis, G. E., W. Mulligan, A. Wormall, and G. Hevesy. Isotopic Tracers: A Theoretical and Practical Manual for Biological Students and Research Workers. 2nd ed. London: University of London. The Athlone Press, 1959.

Francis, G. E., W. Mulligan, A. Wormall, and G. Hevesy. Isotopic Tracers: A Theoretical and Practical Manual for Biological Students and Research Workers. 2nd ed. London: University of London. The Athlone Press, 1959.