Clarke, H., & Lapper, i. I. (1983). <Os >vikings. Verbo.
Chicago Style aipamenaClarke, Helen, and il. Ivan Lapper. <Os >vikings. Verbo, 1983.
MLA aipamenaClarke, Helen, and il. Ivan Lapper. <Os >vikings. Verbo, 1983.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.