BibTeX Reference for “CSS Box Sizing Module Level 4”

@TechReport{Simmons:21:CBS,
  author      = "Jen Simmons and Tab Atkins Jr. and Elika Etemad",
  title       = "{CSS} Box Sizing Module Level 4",
  month       = may,
  note        = "https://www.w3.org/TR/2021/WD-css-sizing-4-20210520/",
  year        = "2021",
  bibsource   = "https://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Working Draft",
  institution = "W3C",
}