Ruppersberg, Klaus; Herzog, Stefanie; Kussler, Manfred W.; Parchmann, Ilka. How to visualize the different lactose content of dairy products by Fearon's test and Woehlk test in classroom experiments and a new approach to the mechanisms and formulae of the mysterious red dyes. Chemistry Teacher International. 2019. doi:10.1515/cti-2019-0008(英语).