TY  - BOOK
AU  - Annie J.Cannon
AU  - Cannon,Annie J.
TI  - The Henry Draper Extension
U1  - B611C12f921 
PY  - 1925///-1928
CY  - Harvard
PB  - Harvard College Observatory
KW  - Astrophysics
KW  - spectra
KW  - Catalogue
ER  -