Heiligmann, Randall B; Winch, Fred E (1996). "Chapter 3: The Maple Resource". In Koelling, Melvin R; Heiligmann, Randall B (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
Gellmann, D (2001). "Pirates, Sugar, Debtors, and Slaves: Political Economy and the case for Gradual Abolition in New York". Slavery & Abolition: A Journal of Slave and Post-Slave Studies. 22 (2): 51–68. doi:10.1080/714005193.
Ruth, Robert H; Underwood, J Clyde; Smith, Clark E; Yang, Hoya Y (1972). "Maple sirup production from bigleaf maple"(PDF). PNW-181. US Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station: 12.
Heiligmann, Randall B; Winch, Fred E (1996). "Chapter 3: The Maple Resource". In Koelling, Melvin R; Heiligmann, Randall B (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
van den Berg, Abby; Perkins, Timothy; Isselhardt, Mark (December 2006). "Sugar Profiles of Maple Syrup Grades"(PDF). Maple Syrup Digest: 12–13. Archived from the original(PDF) on 2013-08-10. Retrieved 2016-07-12.
vermontmaple.org
"Vermont maple sugar". Vermont Maple Sugar Makers Association. 2016. Archived from the original on 31 October 2016. Retrieved 11 July 2016.
"Vermont maple sugar". Vermont Maple Sugar Makers Association. 2016. Archived from the original on 31 October 2016. Retrieved 11 July 2016.
van den Berg, Abby; Perkins, Timothy; Isselhardt, Mark (December 2006). "Sugar Profiles of Maple Syrup Grades"(PDF). Maple Syrup Digest: 12–13. Archived from the original(PDF) on 2013-08-10. Retrieved 2016-07-12.
