First article on the diet problem – Stigler’s diet problem George J. Stigler, "The Cost of Subsistence,” Journal of Farm Economics, 27, 1945, pp. 303-14.
http://www.jstor.org/pss/1231810
Dantzig’s diet problem George Dantzig, “The diet problem,” Interfaces 20: 4 July-August 1990, pp 43-47.
http://www.jstor.org/pss/25061369
Diet Problem Solver: This page, sponsored by the Finite Mathematics and Applied Calculus website, can help you solve a diet problem.
http://www.zweigmedia.com/RealWorld/dietProblem/diet.html
Simplex Method Tool – Type your own linear programming problem, and it will give you the solution. The page is sponsored by the Finite Mathematics and Applied Calculus website.
http://www.zweigmedia.com/RealWorld/simplex.html
Sponsored by the Wolfram Demonstrations Project website, this page presents a visualization of a simple standard linear programming scenario.
http://demonstrations.wolfram.com/ASimpleStandardLinearProgrammingScenario/
From the online textbook - Algorithm Animations for Practical Optimization: A Gentle Introduction
http://optlab-server.sce.carleton.ca/POAnimations2007/Default.html
MIT’s OpenCourseWare: Lecture notes on linear programming
http://ocw.mit.edu/courses/mathematics/18-310c-principles-of-applied-mathematics-fall-2007/lecture-notes/26_27_ln.pdf
Introduction to Linear Programming by John Chinneck, a professor at Carleton University in Ottawa, Canada.
http://www.sce.carleton.ca/faculty/chinneck/po/Chapter2.pdf