@article{Varol1981, 
     author = "Varol, Y. L.", 
     doi = "10.1093/comjnl/24.1.83", 
     issn = "0010-4620", 
     journal = "The Computer Journal", 
     link = "http://comjnl.oxfordjournals.org/content/24/1/83.abstract http://comjnl.oupjournals.org/cgi/doi/10.1093/comjnl/24.1.83", 
     month = "jan", 
     number = "1", 
     pages = "83--84", 
     title = "An Algorithm to Generate All Topological Sorting Arrangements", 
     uri = "http://comjnl.oxfordjournals.org/content/24/1/83.abstract", 
     volume = "24", 
     year = "1981", 
}

Problems: 377