I really would like to use these four books as they give you the freedom to pick & choose, catering to needs & interests, with the bits that you don't cover being completed as self study...a learner-centred approach. As self-study materials, they are self explanatory & learner friendly...ideal to recommend when using a lopsided coursebook or a student asking you for supplementary material. These books would be ideal when working with 1-1 classes & it would also appeal to the more mature class such as the corporate-based class. To sum up, this is certainly one of the ways forward in the provision of course materials. Definitely worth checking out. - http: //developingteachers.com