@article{Zaks1982, 
     author = "Zaks, Shmuel", 
     doi = "10.1016/0020-0190(82)90140-5", 
     issn = "00200190", 
     journal = "Information Processing Letters", 
     keyword = "binary trees,k-ary trees,lexicographic order", 
     link = "f http://linkinghub.elsevier.com/retrieve/pii/0020019082901405", 
     month = "mar", 
     number = "1", 
     pages = "44--48", 
     title = "Generation and ranking of K-ary trees", 
     uri = "f", 
     volume = "14", 
     year = "1982", 
}

Problems: 374