The forth book which a prospective graduate student in economics is expected to have read is
Fundamental Methods of Mathematical Economics by A C Chiang
As mathematics is being increasingly used in economics it’s quite necessary for the students to be familiar with basic and advanced mathematical techniques in Linear Algebra, Calculus, Probability and other important mathematical areas.
This book serves the purpose very well. It’s better to be able to solve the problems at the end of the each chapter such that you know that you understand the concept. The books may take quite some time to finish but it’s worth spending time to understand the book completely.
With this book, readers can use another book
Schaum’s series of mathematical Economics
The beauty of Schaum series book is that it’s written very lucidly with several examples from economics which makes you understand the application of mathematical techniques in economics. In fact… if you don’t have enough time and you want to understand the necessary basic mathematical techniques for economics, probably this is the book.