1. P. C. Thonemann, “The Measurement of ultra high temperatures,” lecture delivered to the Symposium on the Spectroscopic Measurement of High Temperature at The University of Chicago (1960).
2. R. Chabbal, “Recherches expérimentales sur la généralisation de l’emploi du spectromètre Fabry-Perot aux divers, domaines de la spectroscopie,” thesis, University of Paris (1958).