Direct tax case laws_ ca final

hii.....can some give me tips about how  i can memorize direct tax law case name.

I am doing case laws from instiute 'selected case laws'....ths book have almost 100-150 case studies in direct tax ..its not possible for me to memorize each one.....

so ....plz can u give some tips what to do....like what type of case studies is important and all....??