1. Kidnap: Inside the Ransom Business;Shortland,2019
2. 35 Countries Where Americans Are Most Likely to Get Kidnapped: Magazine. April 2019. Available at: https://www.forbes.com/sites/laurabegleybloom/2019/04/25/35-countries-where-americans-are-most-likely-to-get-kidnapped/?sh=7ba81b72bdf1.
3. U.S. State Department K Risk Indicator. Available at: https://travel.state.gov/content/travel/en/News/international-travel-news/k-indicator.html.
4. RISKMAP 21. Available at: https://www.controlrisks.com/-/media/corporate/files/riskmap-2021/riskmap-2021-a3-kidnap-v2.pdf.
5. Hundreds of Nigerian schoolgirls released days after kidnapping. Available at: https://www.cnn.com/2021/03/02/africa/nigeria-schoolgirls-rescued-intl/index.html.