What we are studying now is the fifth edition.
In fact, there is little difference between the fourth and fifth editions of Tongji. Our teacher sometimes uses the fourth edition when giving us lessons.
Where are the books?
If you want to learn by yourself, the first volume is better, and the second volume, the derivation of some theorems may take some effort.
Ps: It's not as simple as what they say, "You can take the final exam at a glance". If you want to study deeply, there are far from enough things in books. I suggest buying some reference books. I used the Guide to Solving Problems in Advanced Mathematics published by Peking University Press and the Guide to Calculus-Question Induction, Method Guidance and Postgraduate Entrance Examination published by National Defense Industry Press, both of which were quite good.
Come on ~ wish you success!