Author not established. Dr. Fitsum. Date not established. EHREA archive: /library/documents/doc-1c50b48f36fc0ac63bf5b3bc/
[1] Dr. Fitsum. Original source: http://www.ehrea.org/drf.php. Preserved original: /library/originals/d6d8763fd7e9f21ef5694c7e3a3a1b9f0b45cc233d2e7d91a320e8fb09287f96.html. SHA-256: d6d8763fd7e9f21ef5694c7e3a3a1b9f0b45cc233d2e7d91a320e8fb09287f96