Language acquisition literature review

Krashen continues  "the long-standing discussion on the familiar topic of whether subconscious language acquisition is more powerful than conscious language learning, with a focus on vocabulary, adding recent studies as well as older ones I missed in previous publications on this topic."
Krashen, S. (2013). Reading and Vocabulary Acquisition: Supporting Evidence and Some Objections. (Stephen Krashen, Iranian Journal of Language Teaching Research, 1 (1): 27-43. www.iljtr.com