One required reading of

One required reading of
 

Are my sentences all correct?

-For this professor's course, one required reading is Romeo and Juliet. In this play, you find 'reason of'; nowadays the usual way is 'reason for'.
-Of this professor's course, one required reading is Romeo and Juliet. In this play, you find 'reason of'; nowadays the usual way is 'reason for'.

For this professor's course, one required reading is ...

Thank you, Rusty, but do you agree if we change the position of the words, OF is also admissible?

- One required reading of this professor's course is Romeo and Juliet.

Yes, that is admissible when you rearrange the wording.

Thank you~

Are they all correct?:

-What I am saying applies only to/for some of you.
-For/to some of you, what I am saying applies/the same thing applies.

Some may use 'for', but 'apply to' is the more common collocation.
So, 'applies only to ...' sounds better.