Zwicky, F. (1933), «Die Rotverschiebung von extragalaktischen Nebeln», Helvetica Physica Acta, 6: 110–127, Bibcode:1933AcHPh...6..110Z See also Zwicky, F. (1937), «On the Masses of Nebulae and of Clusters of Nebulae», Astrophysical Journal, 86, Bibcode:1937ApJ....86..217Z, doi:10.1086/143864
Zwicky, F. (1933), «Die Rotverschiebung von extragalaktischen Nebeln», Helvetica Physica Acta, 6: 110–127, Bibcode:1933AcHPh...6..110Z See also Zwicky, F. (1937), «On the Masses of Nebulae and of Clusters of Nebulae», Astrophysical Journal, 86, Bibcode:1937ApJ....86..217Z, doi:10.1086/143864
Ivanova, Natasha (2008), «110th anniversary of the astrophysicist Fritz Zwicky», Astronomical Observatory and Planetarium of Varna, Bulgarian Astronomical Journal (em búlgaro), 10, Bibcode:2008BlgAJ..10..135I
