Citação APA (7ª ed.)

Schade, L., & Helper, H. R. (1860). A book for the "impending crisis"!: Appeal to the common sense and patriotism of the people of the United States. "Helperism" annihilated! The "irrepressible conflict" and its consequences! Little, Morris.

Citação do estilo Chicago (17ª ed.)

Schade, Louis, e Hinton Rowan Helper. A Book for the "Impending Crisis"!: Appeal to the Common Sense and Patriotism of the People of the United States. "Helperism" Annihilated! The "Irrepressible Conflict" and Its Consequences! Washington, D.C.: Little, Morris, 1860.

Citação MLA (8ª ed.)

Schade, Louis, e Hinton Rowan Helper. A Book for the "Impending Crisis"!: Appeal to the Common Sense and Patriotism of the People of the United States. "Helperism" Annihilated! The "Irrepressible Conflict" and Its Consequences! Little, Morris, 1860.

Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.