Morphological study of the nested planetary nebula Hubble 12Chih-Hao Hsia, Yong Zhang, SeyedAbdolreza Sadjadi, Wayne Chau, Hui-Jie Han and Jian-Feng ChenA&A, 655 (2021) A46DOI: https://doi.org/10.1051/0004-6361/202141508
