Leike, A. (2002). Demonstration of the exponential decay law using beer froth. European Journal of Physics, 23 (1), 21–6. https://doi.org/10.1088/0143–0807/23/1/304 Fisher, N. (2004). The physics of your pint: head of beer exhibits exponential decay. Physics Education, 39 (1), 34–5. https://doi.org/ 10.1088/0031–9120/39/1/F11
