1. 2017 NAICS definitions. https://www.census.gov/eos/www/naics/2017NAICS/2017_Definition_File.pdf. 2017 NAICS definitions. https://www.census.gov/eos/www/naics/2017NAICS/2017_Definition_File.pdf.
2. About Amazon Mechanical Turk. https://www.mturk.com/worker/help. About Amazon Mechanical Turk. https://www.mturk.com/worker/help.
3. Amazon Mechanical Turk. https://www.mturk.com. Amazon Mechanical Turk. https://www.mturk.com.
4. Appen. https://appen.com. Appen. https://appen.com.
5. The CAIDA UCSD AS classification dataset. https://www.caida.org/data/as-classification/. The CAIDA UCSD AS classification dataset. https://www.caida.org/data/as-classification/.