Gupta, S. (2008). Business Statistics 15e (15 th.). Sultan Chand.
Chicago Style aipamenaGupta, S.P. Business Statistics 15e. 15 th. New Delhi: Sultan Chand, 2008.
MLA aipamenaGupta, S.P. Business Statistics 15e. 15 th. Sultan Chand, 2008.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.