Comments on: Tang et al. (2020) 'Bibliometric review of research trends on disinfection by-products in drinking water during 1975–2018' Sep. Purif. Technol., 241: 116741.

• Tang et al. used an inappropriate method to publish a paper in the journal. • The results show a huge difference from the results by using the same method. • This comment pointed out each of the problems. Tang et al. used an inappropriate method to publish a bibliometric paper in Separation and Purification Technology. The results show a huge difference from the results by using the same method. This comment pointed out each of the problems. In addition, some publication and citation indicators were also applied for a new analysis. [ABSTRACT FROM AUTHOR]