Question: In the sentence

> 
> I have a bibliography page which I'd like to **split in/into** sections
> 
> 
> 

which would you rather use: *split in* or *split into*?

Why?

Answer: 
We generally use 'into' to talk about directions and destinations, while we use 'in' to talk about the positions of thing. So you have to use 'split into' in your example because the destinations of the bibliography are the sections. 
However we might use:
(1) 'into' when we think of the division (split) itself; 
(2) 'in' when we think more at the end of division.
I think either one is acceptable. 

The word *in* has well over 20 definitions, and one of them is *[into something](http://www.macmillandictionary.com/dictionary/american/in#in_29).*

So, I have no problem with *divide this page into three sections.* Moreover, I would accept *divide this page in three sections,* although the former seems to sound a bit more natural to me.

As an example of how vexing this could be, I'd probably say:

> 
> Cut this candy bar **in** half.
> 
> 
> 

but also:

> 
> Cut this candy bar **into** thirds.
> 
> 
>