Complex sentence: It appeared often enough to become part of newspaper lore, and "etaoin shrdlu" us listed in the "Oxford English Dictionary" and in the "Random House Webster's Unabridged Dictionary".
Split into simpler sentences: It appeared often enough to become part of newspaper lore. This happened often enough for "etaoin shrdlu" to be listed in the "Oxford English Dictionary" and in the "Random House Webster's Unabridged Dictionary".