Note 420 — Chapter XIV · THE ERBIUM AND YTTERBIUM GROUPS—YTTRIUM AND SCANDIUM
Reading edition
Thalén, Compt. rend. 1879, 88, 642; 1880, 91, 45.
[421] Compt. rend. 1879, 88, 419.
[422] See also Mendelejeff, Ber. 1881, 14, 2821.
[423] Ber. 1880, 13, 1439.