There are several articles and study guides available, but you need to make sure they are from academic sources. These three texts are part of the IGCSE exams for 2018, so there will be lots of non-academic sources out there. Make sure you start by reading the actual texts and taking notes as you read. Then, look for academic sources to help you dig deeper into the material.
1. For the short story "Of White Hairs and Cricket" by Rohinton Mistry, you could read an article called "Changing Family Values in the Fiction of Rohinton Mistry" by K. Maragathavel. The author is from India and has a wonderful perspective on the culture. This essay comes from volume 3, issue 4 of IMPACT: International Journal of Research in Humanities, Arts and Literature, published in April 2015.
To find other articles like this, go to the IMPACT search page to search by title or author.
You can also go through your school library and search for the article "Problems of Selfhood: A Study of Rohinton Mistry's Tales from Firozsha Baag" by Bharathi V. Harishankar, which appears in Littcrit, volume 33, issue 2, published in December 2007.
2. For "Sandpiper" by Adhaf Soueif, look up the academic article "The Scattering of the Self and the Sense of Alienation: Ahdaf Soueif’s Sandpiper" by Ghisae Maskoun Sanjakdar. The article appears in volume 9, issue 1 of the International Review of Social Sciences and Humanities, published in 2015.
3. For "Tyres" by Adam Thorpe, you can learn about the author by looking at the eNotes study guide about him right on this site! On Adam Thorpe's website, there is also a page for his short story collection Shifts, in which "Tyres" was published, that collects reviews of the work.