W. Heitmann; E. Ritter. Production and properties of vacuum evaporated films of thorium fluoride. Applied Optics. 1968, s. 307–309. Dostupné online. PMID20062461.
opticsinfobase.org
W. Heitmann; E. Ritter. Production and properties of vacuum evaporated films of thorium fluoride. Applied Optics. 1968, s. 307–309. Dostupné online. PMID20062461.