Great article on COCOMO estimation.

http://nptel.ac.in/courses/106105087/pdf/m11L28.pdf

GATE answers

http://clweb.csa.iisc.ernet.in/rahulsharma/gate2011key.html

NPTEL CS courses

NPTEL CS courses

Compiler Design

http://nptel.ac.in/courses/Webcourse-contents/IIT-KANPUR/compiler-desing/ui/Course_home-4.htm

nice explanation about fork ()

http://www.careercup.com/question?id=189793

Planar Graph
http://en.wikipedia.org/wiki/Planar_graph

Problems on CFGs

http://www.idt.mdh.se/kurser/cd5560/10_11/examination/KOMPENDIER/ContextFree/Comp-CFL-10.pdf

decidability problems

http://cs.williams.edu/~andrea/cs361/Lectures/lect32.pdf