Bechtel,Helmut. (1981). The manual of cultivated orchid species. Bath press.
Chicago Style aipamenaBechtel,Helmut. The Manual of Cultivated Orchid Species. Great britain: Bath press, 1981.
MLA aipamenaBechtel,Helmut. The Manual of Cultivated Orchid Species. Bath press, 1981.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.