Go!IELTS (Nigeria), no date. — 169 p.
This material was originally packaged for my students, who have since made their desired band scores and referred their friends to it.
I therefore do not doubt that if you would use this workbook as prescribed:
Studying essays assigned for each day;
Writing the Practice Exercise for each day;
Engaging the service of an IELTS expert in assessing your essays and providing you with feedback;
working on his comments, remarks, and recommendations;
not repeating your mistakes;
You will have, by the 20th day, mastered the structure, vocabulary, language, and style needed to produce a top band in your IELTS Writing Task 2 not many days after.
Despite that efforts have been made to ensure this workbook covers as many of the subjects or topics usually written about in IELTS, it is still not exhaustive. So, read and read wide.
Success in IELTS is predictable once you can do the needful.