@article{Bitner1976, 
     author = "Bitner, James R. and Ehrlich, Gideon and Reingold, Edward M.", 
     doi = "10.1145/360336.360343", 
     issn = "00010782", 
     journal = "Communications of the ACM", 
     keyword = "Gray code,combinations,combinatorial computing,compositions,subsets", 
     link = "http://dl.acm.org/citation.cfm?id=360336.360343 http://portal.acm.org/citation.cfm?doid=360336.360343", 
     month = "sep", 
     number = "9", 
     pages = "517--521", 
     publisher = "ACM", 
     title = "Efficient generation of the binary reflected gray code and its applications", 
     uri = "http://dl.acm.org/citation.cfm?id=360336.360343", 
     volume = "19", 
     year = "1976", 
}

Problems: 387