General GMAT Questions and Strategies | Re: Data Sufficiency Books or Guides?

Hi all,

I was wondering if anyone knew of any books that specifically tackle data sufficiency questions?

I am really struggling with this part of the GMAT, everything else seems fairly straight forward but I feel like I just don't have the correct approach to tackling these questions and I try to avoid them.

I want to focus only on this section for a while - could anyone recommend books or guides specific for Data Sufficiency

Thanks,
Sefwow