1. Bernholtz P: Monetary Regimes and Inflation: History, Economic and Political Relationships. 2003, Basle, Switzerland: Edward Elgar Publishing
2. Igumbor EO, Obi CL, Bessong PO, Potgiester N, Mkasi TC: Microbiological analysis of banknotes circulating in the Venda region of Limpopo province, South Africa. Sabinet. 2007, 103: 365-366.
3. Debajit B, Pratap P, Tarun K: Paper currencies, a potential carrier of pathogenic microorganisms. Int J Appl Biol Pharm Technol. 2012, 3: 23-25.
4. Ahmed PS, Nasreen T, Feroza B: Evaluation of the microbial contamination of Bangladesh paper currency notes (Taka) in circulation. Adva BiolRes. 2010, 4: 266-271.
5. Mensah P, Yeboah-Manu D, Owusu-Darko K, Ablordey A: Street foods in Accra, Ghana: how safe are they?. Bull World Heal Organ. 2002, 80: 546-554.