Curzon A.E., Chlebek H.G. (1973). "The observation of face centred cubic Gd, Tb, Dy, Ho, Er and Tm in the form of thin films and their oxidation". J. Phys. F. 3 (1): 1–5. Bibcode:1973JPhF....3....1C. doi:10.1088/0305-4608/3/1/009.
Curzon A.E., Chlebek H.G. (1973). "The observation of face centred cubic Gd, Tb, Dy, Ho, Er and Tm in the form of thin films and their oxidation". J. Phys. F. 3 (1): 1–5. Bibcode:1973JPhF....3....1C. doi:10.1088/0305-4608/3/1/009.