1. 기본 정보
| <colbgcolor=#192b4d><colcolor=white> 출처 | Encyclopædia Britannica |
| 저작자 | Gareth Iwan Jones—eyevine/Redux |
| 저작권 | All Britannica content is royalty-free and cleared for copyright on the condition that it is being used for an educational, non-commercial purpose. |