Related Clues:

• Previously, in poetry
• Word between I's in a famous palindrome
• '___ upon my bed I lay me': Longfellow
• ''Into the brain __ one can think'': Keats
• Middle of the "Able ... Elba" palindrome
• "But I heard him exclaim, ___ he drove ..."
• "Author unknown" byline
• "Auth. unknown"
• Before, in a ballade
• Lyrical preposition
• Before much longer
• Afore's poetic cousin
• Abbr. in a book of quotations
• Before, in a syllable
• Not there, to 11-Down