Burton, W. B. (1970). The Sagittarius spiral arm and the general distribution of hydrogen between 0̊ and 90̊ longitude: Streaming and geometrical effects on the derivation of density / William Butler Burton. Sterrewacht.
Lua i Stíl Chicago (17ú heag.)Burton, W. B. The Sagittarius Spiral Arm and the General Distribution of Hydrogen Between 0̊ and 90̊ Longitude: Streaming and Geometrical Effects on the Derivation of Density / William Butler Burton. Leiden: Sterrewacht, 1970.
Lua MLA (8ú heag.)Burton, W. B. The Sagittarius Spiral Arm and the General Distribution of Hydrogen Between 0̊ and 90̊ Longitude: Streaming and Geometrical Effects on the Derivation of Density / William Butler Burton. Sterrewacht, 1970.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.