Fix link to logic and constraint programming extensions

docs/source/ampl/books/index.md

@@ -123,6 +123,6 @@ anthony-papavasiliou/electricity-markets.md
 
 -   L.S. Lasdon, _[Optimization Theory for Large Systems](http://www.amazon.com/exec/obidos/ISBN=0486419991/amplA/)._ Dover, 2002. _A survey of decomposition, relaxation, column-generation, and compact-basis methods for large-scale optimization, in an inexpensive reprint edition._
 
--   K. Marriott and P.J. Stuckey, _[Programming With Constraints: An Introduction](http://www.amazon.com/exec/obidos/ISBN=0262133415/amplA/)._ MIT Press, 1998. _An introduction to techniques that can provide an alternative to integer programming for highly combinatorial problems._ (See also the [proposed AMPL extensions](https://ampl.com/_archive/first-website/BOOK/bookstore.html../NEW/FUTURE/logic.html) that would take advantage of constraint logic programming solvers.)
+-   K. Marriott and P.J. Stuckey, _[Programming With Constraints: An Introduction](http://www.amazon.com/exec/obidos/ISBN=0262133415/amplA/)._ MIT Press, 1998. _An introduction to techniques that can provide an alternative to integer programming for highly combinatorial problems._ (See also the [AMPL extensions](https://ampl.com/products/ampl/logic-and-constraint-programming-extensions/) that take advantage of constraint logic programming solvers.)
 
 -   J.D. Pinter, _[Global Optimization in Action: Continuous and Lipschitz Optimization: Algorithms, Implementations and Applications](http://www.amazon.com/exec/obidos/ISBN=0792337573/amplA/)._ Kluwer, 1996. _Winner of the 1999 INFORMS Computing Society Prize for Research Excellence in the Interface Between Operations Research and Computer Science._