@article{Rotem1978a, 
     author = "Rotem, Doron and Varol, Y. L.", 
     doi = "10.1145/322077.322082", 
     issn = "00045411", 
     journal = "Journal of the ACM", 
     link = "http://dl.acm.org/citation.cfm?id=322077.322082", 
     month = "jul", 
     number = "3", 
     pages = "396--404", 
     publisher = "ACM", 
     title = "Generation of Binary Trees from Ballot Sequences", 
     uri = "http://dl.acm.org/citation.cfm?id=322077.322082", 
     volume = "25", 
     year = "1978", 
}

Problems: 402