References:
http://astro.physics.ncsu.edu/~cfrohli/2015_FOE/PRESENTATIONS/Grant_Williams_FOE2015.pdf
2015 slides of spectropolarimetry
SNSPOL project
https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=2708&context=all_dissertations
8-2016 Spectropolarimetry of Thermonuclear Supernovae
https://articles.adsabs.harvard.edu/pdf/1991ApJS...77..405J sn 1991 catalog
https://articles.adsabs.harvard.edu/pdf/1990ApJ...352..267J sobolev-p 3-d
https://watermark.silverchair.com/stz2322.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAugwggLkBgkqhkiG9w0BBwagggLVMIIC0QIBADCCAsoGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQM1c5lT5LRzQRyvsvxAgEQgIICm4bYNhE3P6AKom2dsWE6S4_zWfQkQUkEnZ2qzKG1hvhFZighcOtLqMM-aVdGoQQvhXorIi30klVPUeTo7rWLKBaz0LxOVTs8yoao6X0AGgn893-IkK-dazRMqHAekKqQ30x4-atvPVH3IMrmq4UU2dYz5_3N6qwzWo8Yck1iA-Q4vRxO4akeA3Bu_M_ZTCaT-bIQmAm-DS27F0ReDJHxpT2RIPDrJ8pijg-8Dcz67VYvhEbEiaUr2fNC4MQ7A3A9w4B_O68MKkwYXUGchqnzvlHZRqV5PBRETA59viBY1ReM-YHLQaaHcjQPe5m3fowIwIqZClMOWkwKeVjCy8ofp44enS3Die8BX6wx70-BYYWyo-C-nHS6kubyoNlEQdO9G-odEYYW8O9ev7EaqfLqXTnGqZyzyGr9BtyyT5OCvSjrP7jmKsnO2z5F0rtPBdnGyoVHGPRHR3X0cLQFfnWKCoNX3WVbDmLU1lrO2omcXOMi6N1Ioik1OAk25ChIK0a_Wk7c9FJ-CCWGyhBGY1md4qKCMHgND89HXUxkctijRZagIC_9Tsec73g084qCuEvjTZZej3zJOqb1hdW8tY01ZjtCxjCZIsZ2gKMhrQrBgVHFJvND3pB4rrgjJEf94eDEu9fKwyjK3sBY8ZyTQwGFB-QJxGg3mi-TCy42Ps__3CYZAel8QjEaKRFsHZWJMIGeZea-OHkbneJkBsiUQhQaBooqkN3o7_VBdAGeO5Giitc5FCrXg0RGe3yU2cBtpAUa-kmAXmdpyW2pAuX0UJyBVojFMfNT5KmGD5uCPOKVZzKKqCnbjnO3KMG7hFPOPpcPI2wcZWWQ-W7vsTBpNW7iiFb_AfKwqom1WIjsGgq7Sn7oqQHBL-I2VL_mfNI
Lifan et al
https://repositories.lib.utexas.edu/bitstream/handle/2152/34436/spectropolarimetryiasn2007.pdf?sequence=1&isAllowed=y
lifan
https://www.int.washington.edu/talks/WorkShops/int_04_2/People/Nugent_P/pol_nugent.pdf
post 2003 nugent and kasen
https://link.springer.com/content/pdf/10.1007%2F978-3-319-21846-5_110.pdf
37Introduction to Supernova Polarimetry 33 page revie by patat observatuiba
https://arxiv.org/pdf/2106.14589.pdf hristov
Lifan Wang
This paper appears to show that when the velocity gradient is large, the degree of polarization increases:
https://arxiv.org/pdf/1203.4438.pdf
One of the papers I found relevant is https://iopscience.iop.org/article/10.1086/533410.