@article{Er1992, 
     author = "Er, M. C.", 
     doi = "10.1093/comjnl/35.3.306", 
     issn = "0010-4620", 
     journal = "The Computer Journal", 
     link = "http://comjnl.oxfordjournals.org/cgi/doi/10.1093/comjnl/35.3.306", 
     month = "jun", 
     number = "3", 
     pages = "306--308", 
     title = "Efficient Generation of K-Ary Trees in Natural Order", 
     uri = "http://comjnl.oxfordjournals.org/cgi/doi/10.1093/comjnl/35.3.306", 
     volume = "35", 
     year = "1992", 
}

Problems: 344