Author not established. Aster F. Date not established. EHREA archive: /library/documents/doc-0ee099b6d013c591bae50190/
[1] Aster F. Original source: http://www.ehrea.org/Aster.pdf. Preserved original: /library/originals/21d51d5e7f3e434e59e55ab7d18146d1c3095e71b17eb516bfc67f14423e1319.pdf. SHA-256: 21d51d5e7f3e434e59e55ab7d18146d1c3095e71b17eb516bfc67f14423e1319