Hard Sudoku puzzle 50 challenging sudoku puzzles to solve 4*4 sudoku grid
William Liam - Paperback
£5.99
Edited by Phoebe Koundouri, Associate Professor in Economics, DIEES, Athens University of Economics and Business, Greece, Katia Karousakis, Organisation for Economic Cooperation and Development (OECD), Paris, France, Dionysis Assimacopoulos, National Technical University of Athens, Greece, Paul Jeffrey, School of Water Sciences, Cranfield University, UK and Manfred A. Lange, Energy, Environment and Water Research Center, Cyprus Institute