The standard way of doing this is the oxford referencing guide.

http://guides.is.uwa.edu.au/c.php?g=325241&p=2177430

You put a number at the point of reference and then at the end of the document you have the all of full references documented by number.

A crude example:

The results of the trial[1] were disputed by a later report[2] which claimed that


Then at the end, under the title "References":

1. Full reference to the information on the trial.

2. Full reference to the information on the report.

3. etc...



In response to your edit, there is a less formal way of doing this where you would just write "see document x, section y". You sort of answered this yourself.