As IGCSE is a two year course, the Gyaandhara 9 &10 complete and fulfill the requirements of the course. These both the books are good study resources for students.
Gyaandhara 9 helps students to build up the foundation and gives the best practice for all the requirements of reading and writing components.
Gyaandhara 10 is a strong resource to help students to achieve the best result.
Both the books give an example how to go from easy to the difficult way of study that can gives you the confidence, language efficiency and application based knowledge. These books have a good vocabulary building exercises, practice papers and formats.
It's a good resource for reading and writing components.