Farley, A. (2005). Structured Input: Grammar Instruction for the Acquisition Oriented Classroom. Boston: McGraw-Hill.
Lichtman, K., Van Patten, B. (2021). Was Krashen right? Forty years later. Foreign Language Annals, 1-23.
Long, M. (2020). Optimal input for language learning: Genuine, simplified, elaborated, or modified elaborated? Language Teaching, 53(2), 169-182.
Polio, C. (2014). Using authentic materials in the beginning language classroom. CLEAR News. Available here.
VanPatten, B. (2014). Creating Comprehensible Input and Output. The Language Educator, 7(4), 24-26.
Wong, W. & Simard, D. (2016) Focusing on Form in Language Instruction. New York: Routledge.
Zyzik, E. & Polio, C. (2017). Authentic Materials Myths: Applying Second Language Research to Classroom Teaching. Ann Arbor: University of Michigan Press.
Worden, W, (2013).Staying in the Target Language While Teaching Middle School and High School. Dimension, 48. Available here.
Wheeler, G. (2003). Krashen, a Victim of History. TESL Canada Journal, 20(2), 92-99. Available here.