Kepeng Li, Barry Leiba. Email Feedback Report Type Value: not-spam. RFC, 6430:1-7, November 2011. [doi]
@article{rfc6430, title = {Email Feedback Report Type Value: not-spam}, author = {Kepeng Li and Barry Leiba}, year = {2011}, month = {November}, doi = {10.17487/RFC6430}, url = {https://doi.org/10.17487/RFC6430}, researchr = {https://researchr.org/publication/rfc6430}, cites = {0}, citedby = {0}, journal = {RFC}, volume = {6430}, pages = {1-7}, }