Arny, T. T.; Bechis, K. P. (1978). “A model for the cometary nebula NGC 2261”. SAO/NASA ADS Astronomy Abstract Service. 226: 455. Bibcode:1978ApJ...226..455A. doi:10.1086/156627.
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Arny, T. T.; Bechis, K. P. (1978). “A model for the cometary nebula NGC 2261”. SAO/NASA ADS Astronomy Abstract Service. 226: 455. Bibcode:1978ApJ...226..455A. doi:10.1086/156627.