Benjamin Doerr Anand Srivastav Petra Wehr Discrepancy of Cartesian Products of Arithmetic Progressions. 2004 11 Electr. J. Comb. 1 http://www.combinatorics.org/Volume_11/Abstracts/v11i1r5.html db/journals/combinatorics/combinatorics11.html#DoerrSW04