Add references to projection note

[yungyuc]

The projection note (projection.tex) does not have any reference. Please add proper references to the contents in the note.

[EN-Chou]

I've added 2 references to projection.tex, @yungyuc would you please take a look at it?

[tai271828]

I've added 2 references to projection.tex, @yungyuc would you please take a look at it?

You may be interested in using the request button in this pull request #28 to call for his awareness as well.

Click "request" to assign yyc to review the PR for you:

[EN-Chou]

I've added 2 references to projection.tex, @yungyuc would you please take a look at it?

You may be interested in using the request button in this pull request #28 to call for his awareness as well.

Click "request" to assign yyc to review the PR for you:

Thank you for this information!

[yungyuc]

@EN-Chou Once you file a new issue for improving the references, this can be closed. Alternately, you may continue with this issue for the improvement. Either way is good.

[EN-Chou]

@EN-Chou Once you file a new issue for improving the references, this can be closed. Alternately, you may continue with this issue for the improvement. Either way is good.

Noted, thank you.