@article{Zaks1979, 
     author = "Zaks, Shumel and Richards, D.", 
     doi = "10.1137/0208006", 
     issn = "0097-5397", 
     journal = "SIAM Journal on Computing", 
     keyword = "1,1 leaves,2,all k-ary trees with,and,hence no,introduction,lattice path,lexicographic order,motivated by the problem,n nodes,no,of generating,ordered tree,problem for all trees,ranking,ranking and unranking,t,unranking,we solved the analogous,with ni", 
     language = "en", 
     link = "http://epubs.siam.org/doi/abs/10.1137/0208006", 
     month = "feb", 
     number = "1", 
     pages = "73--81", 
     publisher = "Society for Industrial and Applied Mathematics", 
     title = "Generating Trees and Other Combinatorial Objects Lexicographically", 
     uri = "http://epubs.siam.org/doi/abs/10.1137/0208006", 
     volume = "8", 
     year = "1979", 
}

Problems: 397