TY  - BOOK
AU  - Zwaan, C.
TI  - Sunspot models: a study of sunspot spectra
PY  - 1965///
CY  - D'Utrecht
PB  - L' Observatoire D' Utrecht
KW  - Astronomy and Astrophysics Thesaurus
KW  - Sun
KW  - Sunspots
ER  -