Gamma-ray polarimetry of the Crab pulsar observed by POLAR. - Li, Han-Cheng; Produit, Nicolas; Zhang, Shuang-Nan; Kole, Merlin; Sun, Jian-Chao; Ge, Ming-Yu; De Angelis, Nicolas; Hulsman, Johannes; Li, Zheng-Heng; Song, Li-Ming; Tymieniecka, Teresa; Wu, Bo-Bing; et al. (Monthly Notices of the Royal Astronomical Society, 2022)