TY  - BOOK
AU  - Lyttkens,Ejnar
TI  - Problems of Dark Nebulae, Treated by the Method of Moments
T2  - Nova Acta Regiae Societatis Scientiarum Upsaliensis. Uppsala Astronomiska Observatoriums Annalar, Band 2 ; 
PY  - 1950///
CY  - Upsala : 
PB  - Almquist & Wiksell, 
ER  -