1. Recurrence Equation  
   Eric Weisstein, World of Mathematics, Wolfram Res., Inc., Champaign, IL  
2. Recurrence Relation  
   Wikipedia, the free Encyclopedia, Wikimedia Foundation  
3. Difference Equations  
   David Smith, Math. Dept., Duke University, Durham, NC  
4. Linear Filters  
   Joshua Holden, Math. Dept., Duke University,  Durham, NC  
5. First-order difference equations  
   Martin J. Osborne, Economics Dept., University of Toronto, Canada  
6. Second-order difference equations  
   Martin J. Osborne, Economics Dept., University of Toronto, Canada  
7. Recursion -- Doing It Again  
   William D. Shoaff, Computer Sciences, Florida Institute of Technology, Melbourne, FL
8. Difference equations and system representations  
   Control Tutorials for Matlab, Regents of the University of Michigan, Ann Arbor, MI
9. Difference Equations  
   Sean Mauch, Applied and Computational Math., California Inst. Tech., Pasadena, CA
10. Solving Linear Constant-Coefficient Difference Equations  
    Richard Baraniuk, Connexions Project, Rice University, Houston, TX   
11. Difference Equations  
    Keith L. Jones, Physics Dept., The University of Queensland St. Lucia, Brisbane, Australia
12. The Solution of Macroeconomic Difference Equations  applet  
    Thayer Watkins, Economics Dept., San Jose State Univ., Jose State , CA  
13. Difference Equations Lab  applet  
    Andrew Bennett, David Yetter, Math. Dept., Kansas State Univ., Manhattan, KS
14. Difference Equation  
    Julius O. Smith, Center for Computer Research in Music and Acoustics, Stanford Univ., CA  
15. Difference Equation - Z-transform solution  
    Michael Haag, The Connexions Project, Rice University, Houston, TX
16. Difference Equation and Z-Transform  
    John Ting-Yung Wen, Electrical  Computer Eng., Rensselaer Polytechnic Inst., Troy, NY
17. Higher Order Linear Difference Equations / Discrete Dynamical Systems  PDF  
    Ignatios Vakalis, Math. Dept. Capital University, Columbus, OH  
18. Difference Equations  PDF
    Martin Sommer, Economics Dept., Johns Hopkins University, Baltimore, MD
19. Difference equations  PDF  
    James Davidson, Econometrics Dept., Cardiff Business School, Cardiff , U. K.
20. Difference Equations  PDF  
    M. Sami Fadali, Electrical Engineering, University of Nevada, Reno, NV
21. Direct Solution of Difference Equations  PDF   
    Tom Chmielewski, Electrical and Computer Engineering, Drexel University, Philadelphia, PA
22. Solving Difference Equation and Introduction to DTFT   PDF  
    Ruifeng Zhang, Electrical and Computer Engineering, Drexel University, Philadelphia, PA
23. Discrete-time Systems and the z-Transform  PDF  
    B. C. Chang, Mechanical Enginering Dept., Drexel Univ., Philadelphia, PA  
24. The analysis of a nonlinear difference equation occurring in dynamical systems  PDF  
    Per Gustaf Reinhall, California Institute of Technology, Pasadena, CA  

(c) John H. Mathews 2006