Here just before section 4, I was asked to make a .bib file that contains three bibliographic references. So far the examples I've seen, it contains only one reference to data. To implement three references, should I write like this:
@book{Books,
title="Microprocessor and Interfacing.",
author="Douglas V. Hall.",
title="The Elements of Style. ",
author="W. Strunk and E.B. White.",
title="The Theory of Everything ",
author="Stephen Hawking",
}
And how do I call it from .tex file, like this:
\bibliogrphy{online2}
\bibliographystyle{ieeetr}
where online2 is the folder where both the .bib and .tex files are.
And how to show only two contents like it's said in the image(just before section 4)? Is there anything like indexing system?
And another thing is, how to implement the side by side view? Like section 1 is on the left side and section 4 is on the right?

bibtex. Using bibtex: a short guide. – Alan Munn Apr 29 '17 at 16:10biblatexcompatibility, but the answers are applicable more generally.) Jabref (cross-platform) and BibDesk (Mac) are the two most widely used. – Alan Munn Apr 29 '17 at 16:18@book{key, ...}code in the database reference is only for one entry, so with one field and only one author field (and usually some others fields). The "key" part is the identifier of that reference, so you should write@book{keya, ...} @book{keyb, ...} @book{keyc, ...}for tree books. Pay attention to Alan comment. JabRef will help you to understand this syntax. – Fran Apr 30 '17 at 03:52