@techreport{weko_106912_1,
   author	 = "Katsuhisa,Yamanaka and Shin-ichiNakano",
   title	 = "Enumeration, Counting, and Random Generation of Ladder Lotteries",
   year 	 = "2014",
   institution	 = "Department of Computer Science, Gunma University, Department of Electrical Engineering and Computer Science, Iwate University",
   number	 = "20",
   month	 = "nov"
}