Open Courses

Peking University - https://www.coursera.org/course/dsalgo

Carnegie Mellon University (Spring 2013) - http://www.cs.cmu.edu/~guyb/realworld.html

Stanford University (05-06) - http://theory.stanford.edu/~rajeev/cs361.html

Stanford University Coursera - https://class.coursera.org/algo-004/lecture/preview

University of Berkley (Spring 2013) - http://www.cs.berkeley.edu/~jrs/61b/

Princeton University Coursera - https://class.coursera.org/algs4partI-003/lecture/index

MIT (Fall 2011) - http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-006-introduction-to-algorithms-fall-2011/

Dictionary of Data Structures - http://xlinux.nist.gov/dads//

http://u.cs.biu.ac.il/~moshe/ds1.html

http://www.eyrie.org/~eagle/reviews/books/0-201-63361-2.html

Recursion

http://introcs.cs.princeton.edu/java/23recursion/

http://my.safaribooksonline.com/book/programming/java/9780132770873/recursion/ch18lev1sec14

http://www.home.hs-karlsruhe.de/~pach0003/informatik_1/aufgaben/en/recursion.html

http://www.cs.utah.edu/~germain/PPS/Topics/recursion.html

Sorting

http://www.cs.ubc.ca/~harrison/Java/sorting-demo.html

BIG O

http://www.math.dartmouth.edu/~m25f11/Programming/assign1.pdf

https://www.cs.auckland.ac.nz/courses/compsci220s1t/lectures/lecturenotes/GG-lectures/220exercises1.pdf

http://www2.cs.uregina.ca/~mouhoubm/=postscript/=c3620/solmidtW06.pdf