- Ullman, Douglas Jr. "Christmas Bells: A Christmas Carol's Civil War Origin." Civil War Trust. 11/15/16. <http://www.civilwar.org/education/history/on-the-homefront/christmas-bells/christmas-bells.html>.
- Meyer, Don. "I Heard the Bells on Christmas Day." Huffington Post. 11/15/16. <http://www.huffingtonpost.com/don-meyer-phd/i-heard-the-bells-on-chri_b_2316476.html?utm_hp_ref=books&ir=Books>.
- Staff, Harriet. "How Longfellow’s ‘Christmas Bells’ became ‘I Heard the Bells on Christmas Day’." Poetry Foundation. 11/15/16. <https://www.poetryfoundation.org/harriet/2012/12/how-longfellows-christmas-bells-became-i-heard-the-bells-on-christmas-day/>.