TODO: Lee (2004): a survey on history of NLP
- Allen, Natural Language Understanding. Redwood City, CA: Benjamin/Cummings, 1987.
- Rapaport, W. J. (1988). Syntactic semantics: Foundations of computational natural-language understanding (pp. 81-131). Springer Netherlands.
- the explosion of user-generated content
- the outbreak of deceptive phenomena such as web-trolling and opinion spam