PAK Electronic Flash Cards
They summarize the key points in outline format to quickly refresh all the important topics in the readings. The flash cards are in PDF, and PNG format. You can use it in your handheld device (e.g. iPhone, Android, iPad, etc). 
 
Bonus: PAK Anki Flash Cards
The purpose of the PAK Anki Flash Cards is to strengthen your memory on the materials in the syllabus. The PAK Anki Flash Cards are in Anki format. You can save them into your smartphone and review them anywhere you want (e.g. in gym, in train, etc). 
 
Bonus: PAK Electronic Condensed Summary
It summarizes the key concepts and examples in the readings so that you can quickly refresh all the important topics. At the same time, you can see how the topics are linked to the syllabus so that you can also keep the whole picture in mind.