✓

@ebook{           book:293524,
  Author        = "Steel, Duncan",
  date-added    = "2020-04-10 11:05:14 +0200",
  date-modified = "2020-04-10 11:05:14 +0200",
  ISBN          = "9780471404217,0471404217",
  Keywords      = "history of calendars",
  Publisher     = "Wiley",
  Title         = "Marking time: The epic quest to invent the perfect calendar",
  URL           = "http://gen.lib.rus.ec/book/index.php?md5=868B5414285E120604B80C86CD453447",
  Year          = "2000",
  bdsk-url-1    = "http://gen.lib.rus.ec/book/index.php?md5=868B5414285E120604B80C86CD453447"
}

@ebook{ book:293524, Author = "Steel, Duncan", date-added = "2020-04-10 11:05:14 +0200", date-modified = "2020-04-10 11:05:14 +0200", ISBN = "9780471404217,0471404217", Keywords = "history of calendars", Publisher = "Wiley", Title = "Marking time: The epic quest to invent the perfect calendar", URL = "http://gen.lib.rus.ec/book/index.php?md5=868B5414285E120604B80C86CD453447", Year = "2000", bdsk-url-1 = "http://gen.lib.rus.ec/book/index.php?md5=868B5414285E120604B80C86CD453447" }