BibTeX Reference for “CSS Basic User Interface Module Level 4”

@TechReport{Rivoal:21:CBU,
  author      = "Florian Rivoal",
  title       = "{CSS} Basic User Interface Module Level 4",
  month       = mar,
  note        = "https://www.w3.org/TR/2021/WD-css-ui-4-20210316/",
  year        = "2021",
  bibsource   = "https://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Working Draft",
  institution = "W3C",
}