Schwarz, H. E. (2006). 3D photoionization structure and distances of Planetary Nebulae III. NGC 6781. Universidade Nove de Julho.
Chicago Style (17th ed.) CitationSchwarz, Hugo E. 3D Photoionization Structure and Distances of Planetary Nebulae III. NGC 6781. Universidade Nove de Julho, 2006.
MLA (9th ed.) CitationSchwarz, Hugo E. 3D Photoionization Structure and Distances of Planetary Nebulae III. NGC 6781. Universidade Nove de Julho, 2006.
Warning: These citations may not always be 100% accurate.