Citazione Stile APA (7a Edizione)

Soike, L. J. (2013). Necessary courage: Iowa's Underground Railroad in the struggle against slavery. University of Iowa Press.

Citazione stile Chigago Style (17a edizione)

Soike, Lowell J. Necessary Courage: Iowa's Underground Railroad in the Struggle Against Slavery. Iowa City: University of Iowa Press, 2013.

Citatione MLA (9a ed.)

Soike, Lowell J. Necessary Courage: Iowa's Underground Railroad in the Struggle Against Slavery. University of Iowa Press, 2013.