Author not established. The challenge faces to the ELM in the 1960. Date not established. EHREA archive: /library/documents/doc-cd4303c89e6b1953f3faa391/
[1] The challenge faces to the ELM in the 1960. Original source: http://www.ehrea.org/1952chal.php. Preserved original: /library/originals/f4664ef08be4f0dc87875b8ce5f769c4a6fbf882e9e62f497954931c2d47e5da.html. SHA-256: f4664ef08be4f0dc87875b8ce5f769c4a6fbf882e9e62f497954931c2d47e5da