Number,

Your source may have a volume or issue number or both. Abbreviate volume to “vol.” and issue number to “no.” Follow the number with a comma. For other types of numbers such as television episodes or government reports, write out the whole word (e.g. season 3, episode 6; report 52-315).

Examples:

Marchetti-Mercer, Maria C. “Those Easily Forgotten: The Impact of Emigration on those Left Behind.” Family Process, vol. 52, no. 3, Sept. 2012, pp.376-390.

Kunz, Jean Lock. Being Young and Visible: Labour Market Access among Immigrant and Visible Minority Youth: Final Report. Working paper SP-581-08-03E, Human Resources Development Canada, Applied Research Branch, 2003.