1. Marshall, C., Rossman, G.B.: Designing Qualitative Research, 6th edn. Sage (2016)
2. Scalabrino, S., Geremia, S., Pareschi, R., Bogetti, M., Oliveto, R.: Freelancing in the economy 4.0: how information technology can (really) help. In: Social Media for Knowledge Management Applications in Modern Organizations, pp. 290–314. IGI Global (2018)
3. The JobStreet website (2018). https://www.jobstreet.com.my
4. The Monster website (2018). http://www.monster.com.my/
5. Satzinger, J.W., Jackso, R.B., Burd, S.D.: Object-Oriented Analysis and Design With the Unified Process, 1st edn. Cengage Learning, Boston (2005)