http://markov.tistory.com/2http://markov.tistory.com/3http://markov.tistory.com/13http://markov.tistory.com/14http://www.cems.uvm.edu/~lakobati/AppliedUGMath/other_Google/Wills.pdfhttp://www.cs.helsinki.fi/u/linden/teaching/irr06/papers/petteri_huuhka_google_paper.pdf
손님