During the study of linear algebra, several asistant materials are referenced:

- The opencourse 18.06 from Gilbert Strang. From Strang’s home, many valuable materials are available.
- The textbook
*Introduction to Linear Algebra*by Gilbert Strang. - The textbook
*Linear Algebra Done Right*by Sheldon Axler. You can get an abridged version of*Linear Algebra Done Right*from Axler’s homepage. - The textbook
*Matrix Analysis and Applied Linear Algebra*by Carl D. Meyer.

By following Professor Strang, I got an overview of the four spaces of one matrix. Actually, I learnt the 18.06 from the MIT OCW more than one time. After each time, my understanding of linear algebra was deepened.