APA (7th ed.) Citation

McTighe, J., & Wiggins, G. P. (2013). Essential questions: Opening doors to student understanding. ASCD.

Chicago Style (17th ed.) Citation

McTighe, Jay, and Grant P. Wiggins. Essential Questions: Opening Doors to Student Understanding. Alexandria, Va. USA: ASCD, 2013.

MLA (8th ed.) Citation

McTighe, Jay, and Grant P. Wiggins. Essential Questions: Opening Doors to Student Understanding. ASCD, 2013.