Wallenquist, Å. (1929). A photometric research on two open clusters in Cassiopeia (Messier 52 and N. G. C. 663). Almqvist & Wiksell.
Chicago Style (17th ed.) CitationWallenquist, Åke. A Photometric Research on Two Open Clusters in Cassiopeia (Messier 52 and N. G. C. 663). Stockholm: Almqvist & Wiksell, 1929.
MLA (9th ed.) CitationWallenquist, Åke. A Photometric Research on Two Open Clusters in Cassiopeia (Messier 52 and N. G. C. 663). Almqvist & Wiksell, 1929.
Warning: These citations may not always be 100% accurate.