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2. Methodological triangulation: an approach to understanding data
3. No end in sight: Why the end demand movement is the wrong focus for efforts to eliminate human trafficking;Berger S. M.;Harvard Journal of Law & Gender,2012
4. Snowball Sampling: Problems and Techniques of Chain Referral Sampling
5. Boonkong, C. (2018). Thai woman masterminded a sex ring that sparked the biggest police raid in German history. Thai examiner. https://www.thaiexaminer.com/thai-news-foreigners/2018/05/07/thai-woman-sex-ring-biggest-police-raid-german-history-transsexual-germany-thailand/