^The party is widely described as social democratic:
Bryan Evans; Ingo Schmidt (2012). Social Democracy After the Cold War. Athabasca University Press. ISBN 978-1-926836-87-4.
Melody Hessing; Michael Howlett; Tracy Summerville (2005). Canadian Natural Resource And Environmental Policy: Political Economy And Public Policy. UBC Press. p. 176. ISBN 978-0-7748-1181-1.
Rand Dyck (2011). Canadian Politics. Cengage Learning. p. 219. ISBN 978-0-17-650343-7.
Norman Penner (1992). From Protest to Power: Social Democracy in Canada 1900-Present. James Lorimer & Company. ISBN 978-1-55028-384-6.
John M. Herrick; Paul H. Stuart (2004). Encyclopedia of Social Welfare History in North America. SAGE. p. 337. ISBN 978-0-7619-2584-2.
John Herd Thompson; Stephen J. Randall (2002). Canada and the United States: Ambivalent Allies. University of Georgia Press. p. 309. ISBN 978-0-8203-2403-6.
Ian McLeod (1994). Under Siege: The Federal Ndp in the Nineties. James Lorimer & Company. ISBN 978-1-55028-454-6.
Keith Archer (1990). Political Choices and Electoral Consequences: A Study of Organized Labour and the New Democratic Party. McGill-Queens. p. 15. ISBN 978-0-7735-0744-9.
Richard Collin; Pamela L. Martin (2012). An Introduction to World Politics: Conflict and Consensus on a Small Planet. Rowman & Littlefield. p. 209. ISBN 978-1-4422-1803-1. Retrieved July 18, 2013.
^Pamela Behan (2012). Solving the Health Care Problem: How Other Nations Succeeded and Why the United States Has Not. SUNY Press. ISBN 978-0-791-48135-6.