1. World coffee trade (1963 – 2013): a review of the markets, challenges and opportunities facing the sector;ICO;Reviev 112th Int. Coffee Counc.,2014
2. http://www.ico.org/trade_statistics.asp, (n.d.).
3. European Coffee Report 2018/2019,2019
4. https://www.mordorintelligence.com/industry-reports/coffee-market?gclid=CjwKCAjw-7LrBRB6EiwAhh1yX6c6GOFYqUaxXYgMeNoAF2DEL2SHttli0jrQ_G5WSKqY0q7ue_ETGhoCQ1EQAvD_BwE, Coffee Mark. - Growth, Trends Forecast. (2019 - 2024). (n.d.).
5. Spent coffee grounds: a review on current research and future prospects;Campos-Vega;Trends Food Sci. Technol.,2015