CEI. (1990). HANDBOOK OF STATISTICS. C E I.
Chicago Style aipamenaCEI. HANDBOOK OF STATISTICS. C E I, 1990.
MLA aipamenaCEI. HANDBOOK OF STATISTICS. C E I, 1990.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.
CEI. (1990). HANDBOOK OF STATISTICS. C E I.
Chicago Style aipamenaCEI. HANDBOOK OF STATISTICS. C E I, 1990.
MLA aipamenaCEI. HANDBOOK OF STATISTICS. C E I, 1990.