Prerau, David (2006). "Early adoption and U.S. Law". Daylight Saving Time. Web Exhibit. Diarsipkan dari versi asli(HTML) tanggal 2016-01-06. Diakses tanggal 23 April 2007.
webexhibits.org
Prerau, David (2006). "Early adoption and U.S. Law". Daylight Saving Time. Web Exhibit. Diarsipkan dari versi asli(HTML) tanggal 2016-01-06. Diakses tanggal 23 April 2007.