{
  "name": "How the liter was defined, 1879–1979",
  "desc": "One row per decision on the liter, from the 1879 name to the 1979 symbols, including the 1901 water definition and the 1964 return to the cubic decimeter.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "The Yardstick Almanac",
  "url": "https://theyardstickalmanac.com/units/kilogram-definition/",
  "from": [
    "CGPM 1901 Declaration 1, 1960 Resolution 13 and 1964 Resolution 6 on the litre, as published by the BIPM",
    "BIPM, The International System of Units (SI), 9th edition, version 4.01 (June 2026), CC BY 4.0"
  ],
  "how": "Compiled by The Yardstick Almanac from the data listed",
  "data_by": [
    "CGPM decisions of 1901, 1960 and 1964 and the SI Brochure, 9th edition, version 4.01, by the BIPM, CC BY 4.0 (adapted: summarized one decision per row); 2026-11-01"
  ]
}