F. Sabbadin, A. Bianchini, S. Ortolani & F. Strafella: The structure of NGC 3587, the Owl nebula, Monthly Notices of the Royal Astronomical Society, vol. 217, Dec. 1, 1985, p. 539-549
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Y. H. Chu, K. Y. L. Su, J. Bilikova, R. A. Gruendl, O. De Marco, M. A. Guerrero, A. C. Updike, K. Volk & T. Rauch Spitzer 24 μm Survey for Dust Disks around Hot White Dwarfs, The Astronomical Journal, Volume 142, Issue 3, article id. 75, p. 3 (2011)