There is one more kind of matter: Doesn't matter

The same reason why all others are allowing that.

Unless Apple already has backdoors for NSA on OSX and iOS.

Yes, rightly said so. And in most of the cases it is considered to be "good" to cite from "respectable" journals. Who wants citations from obscure journals nobody has heard about?

I agree to this. Slashdot post for Future : More Researchers Moving On To Zotero! It is not just for fun Elsevier have taken up Mendeley, soon your papers will be scrutinized whether they have been downloaded legally or you have an unauthorized copy of the same. And if found using unauthorized copies, you know what they did to Aaron.

Edward Tufte in Cognitive Style of Powerpoint has a lot to say about slides their format and content and is against their indiscriminate uset. This is from a perspective of an information designer. http://www.edwardtufte.com/tufte/books_pp "Alas, slideware often reduces the analytical quality of presentations. In particular, the popular PowerPoint templates (ready-made designs) usually weaken verbal and spatial reasoning, and almost always corrupt statistical analysis. What is the problem with PowerPoint? And how can we improve our presentations?"

See also lot of non-fiction books by Yakov Perelman http://en.wikipedia.org/wiki/Yakov_Perelman.

Surreal Number by Donald Knuth Nearly 30 years ago, John Horton Conway introduced a new way to construct numbers. Donald E. Knuth, in appreciation of this revolutionary system, took a week off from work on The Art of Computer Programming to write an introduction to Conway's method. Never content with the ordinary, Knuth wrote this introduction as a work of fiction--a novelette. If not a steamy romance, the book nonetheless shows how a young couple turned on to pure mathematics and found total happiness. The book's primary aim, Knuth explains in a postscript, is not so much to teach Conway's theory as "to teach how one might go about developing such a theory." He continues: "Therefore, as the two characters in this book gradually explore and build up Conway's number system, I have recorded their false starts and frustrations as well as their good ideas. I wanted to give a reasonably faithful portrayal of the important principles, techniques, joys, passions, and philosophy of mathematics, so I wrote the story as I was actually doing the research myself."...It is an astonishing feat of legerdemain. An empty hat rests on a table made of a few axioms of standard set theory.Conway waves two simple rules in the air, then reaches into almost nothing and pulls out an infinitely rich tapestry of numbers that form a real and closed field. Every real number is surrounded by a host of new numbers that lie closer to it than any other "real" value does. from http://www.amazon.com/Surreal-Numbers-Donald-Knuth/dp/0201038129

Oh actually, going to Mars is way of getting rid of the traffic problem. As you must be knowing there is no traffic on Mars. That is the brilliant idea. As for the electricity problem, they are planning to construct nuclear power plants on Mars (of course with help from the West) whose surplus will be beamed back to India to take out the regular blackouts. Who knows what else they are up to?

I have thrown out windows long back.