Kasen, D., Woosley, S., & Heger, A. (2011). PAIR INSTABILITY SUPERNOVAE: LIGHT CURVES, SPECTRA, AND SHOCK BREAKOUT. The Astrophysical Journal, 734(2), 102. doi: 10.1088/0004-637x/734/2/102. Available online at https://iopscience.iop.org/article/10.1088/0004-637X/734/2/102/meta. According to Kasen et al (2011).
Bianchi, L. & Grewing, M (1987). NGC 40 : IUE observations of the nucleus. Astronomy and Astrophysics, 181, 85-95. https://ui.adsabs.harvard.edu/abs/1987A%26A...181...85B/abstract. According to Bianchi.L et al (1987)
Sandage, A., & Tammann, G. A. (1971). Absolute Magnitudes of Cepheids. III. Amplitude as a Function of Position in the Instability Strip: a Period-Luminosity Relation. Astrophysical Journal, 167, 293. https://ui.adsabs.harvard.edu/abs/1971ApJ...167..293S/abstract. According to Sandage, A., & Tammann, G. A. (1971).
Wielgórski, P. et al. (2017). A Precision Determination of the Effect of Metallicity on Cepheid Absolute Magnitudes inVIJHKBands from Magellanic Cloud Cepheids. The Astrophysical Journal, 842(2), 116. https://iopscience.iop.org/article/10.3847/1538-4357/aa7565/meta. According to Wielgórski, P. et al. (2017).
Balaz, L. G. et al (1996). Medium resolution spectroscopy of Hα objects in IC 1396. Astronomy and Astrophysics, 311, 145-151. https://ui.adsabs.harvard.edu/abs/1996A%26A...311..145B/abstract. According to Balaz, L. G. et al (1996).
Weikard, H. et al (1996). The structure of the IC1396 region. Astronomy and Astrophysics, 309, 581-611. https://ui.adsabs.harvard.edu/abs/1996A%26A...309..581W/abstract. According to Weikard, H. et al (1996).
Sabbadin, F., Bianchini, A., & Hamzaoglu, E.(1983). Internal motions in planetary nebulae : NGC 7354, I 289 and HU 1-2. Astronomy and Astrophysics, 51, 119-126. https://ui.adsabs.harvard.edu/abs/1983A%26AS...51..119S/abstract. According to Sabbadin, F., Bianchini, A., & Hamzaoglu, E.
Moreno-Corral, M. A. et al (1993). H-alpha interferometric, optical and near IR photometric studies of star forming regions. I. The Cepheus B/Sh2-155/Cepheus OB3 association complex. Astronomy and Astrophysics, 273, 619-632. https://ui.adsabs.harvard.edu/abs/1993A%26A...273..619M/abstract. According to Moreno-Corral, M. A. et al (1993).