Small update

Z-Training can't be accessed (http://www.codah.club/) maybe doesn't exist anymore. The Algorithm Design Manual has third edition and the wiki link is changed.

Author: MTrajK

README.md

@@ -157,7 +157,7 @@ Several books that have made an impression on me:
 1. [Grokking Algorithms by Aditya Bhargava](https://www.goodreads.com/book/show/22847284-grokking-algorithms-an-illustrated-guide-for-programmers-and-other-curio) - **The best** book for complete beginners in algorithms! I wish this book existed when I started learning algorithms.
 2. [Introduction to Algorithms by CLRS](https://www.goodreads.com/book/show/6752187-introduction-to-algorithms) - This book is called the "bible textbook of algorithms" by many programmers.
 3. [Algorithms by Robert Sedgewick & Kevin Wayne](https://www.goodreads.com/book/show/10803540-algorithms) - These authors are instructors of the previously mentioned Coursera courses: [Algorithms Part 1](https://www.coursera.org/learn/algorithms-part1) and [Algorithms Part 2](https://www.coursera.org/learn/algorithms-part2). Also, this book has an excellent and free [site](http://algs4.cs.princeton.edu) with exercises, presentations, and examples.
-4. [The Algorithm Design Manual by Steven Skiena](https://www.goodreads.com/book/show/425208.The_Algorithm_Design_Manual) - The book describes many advanced topics and algorithms and it focuses on real-life practical examples. This book has [one](http://www.algorist.com) of the best sites with resources ([solutions](http://www.algorist.com/algowiki/index.php/The_Algorithms_Design_Manual_(Second_Edition)), [algorithms and data structures](http://www.algorist.com/algorist.html), [python implementations](http://www.algorist.com/languages/Python.html)).
+4. [The Algorithm Design Manual by Steven Skiena](https://www.goodreads.com/book/show/425208.The_Algorithm_Design_Manual) - The book describes many advanced topics and algorithms and it focuses on real-life practical examples. This book has [one](http://www.algorist.com) of the best sites with resources ([solution wiki](https://algorist.com/algowiki/index.php/), [algorithms and data structures](http://www.algorist.com/algorist.html), [python implementations](http://www.algorist.com/languages/Python.html)).
 5. [Algorithms by S. Dasgupta, C. Papadimitriou, and U. Vazirani](https://www.goodreads.com/book/show/138563.Algorithms) - This book is an official book for algorithms and data structures classes in several famous universities.
 6. [Competitive Programming 3 by Steven Halim & Felix Halim](https://www.goodreads.com/book/show/22820968-competitive-programming-3) - A great book that prepares you for competitive programming (not for complete beginners). You can learn many things and tricks about competitive programming. *But if your goal is to prepare for competitive programming then choose a faster language than Python, **C/C++** (or Java, it's faster than Python but not like C/C++).*
 7. [Cracking the Coding Interview by Gayle Laakmann McDowell](https://www.goodreads.com/book/show/29350585-cracking-the-coding-interview) - A bit different from the previous books. Prepares you for coding interviews using great coding problems.
@@ -190,7 +190,6 @@ If the problems from [LeetCode](https://leetcode.com/) are not enough and you ne
 - [Exercism](https://exercism.io/)
 - [CodeFu](https://codefu.mk/)
 - [Mendo](https://mendo.mk/Welcome.do)
-- [Z-Training](http://www.codah.club/)
 - [Codewars](http://www.codewars.com/)
 - [Wolfram Challenges](https://challenges.wolfram.com/)
 - [Google's Coding Competitions](https://codingcompetitions.withgoogle.com/)