Miyako Ohkubo Fumiaki Miura Masayuki Abe Atsushi Fujioka Tatsuaki Okamoto An Improvement on a Practical Secret Voting Scheme. 225-234 1999 conf/isw/1999 ISW http://link.springer.de/link/service/series/0558/bibs/1729/17290225.htm db/conf/isw/isw1999.html#OhkuboMAFO99