books.google.com - This text is designed for an introductory probability course at the university level for undergraduates in mathematics, the physical and social sciences, engineering, and computer science. It presents a thorough treatment of probability ideas and techniques necessary for a firm understanding of the ...http://books.google.com/books/about/Introduction_to_Probability.html?id=14oq4uWGCkwC&q=probability+vector&utm_source=gb-gplus-shareIntroduction to Probability