Cullen Jennings, Julian F. Reschke. vCard Extensions for Instant Messaging (IM). RFC, 4770:1-7, January 2007. [doi]
@article{rfc4770, title = {vCard Extensions for Instant Messaging (IM)}, author = {Cullen Jennings and Julian F. Reschke}, year = {2007}, month = {January}, doi = {10.17487/RFC4770}, url = {https://doi.org/10.17487/RFC4770}, researchr = {https://researchr.org/publication/rfc4770}, cites = {0}, citedby = {0}, journal = {RFC}, volume = {4770}, pages = {1-7}, }