The image below describes an integration technique known (at least in Spanish) as "El Método Alemán," which translates to "The German Method" in English. I haven't found any references to this technique under the name "German Method" in English. This site cites the book Demidovich, B. P., and Aparicio, E. (2001). 5000 problemas de análisis matemático. Madrid, Spain: Thomson.
This video (in Spanish) gives an example of the application of the technique.
Does anyone know exactly what the origin of this method is? That is, who is the author and where was it published?