The edition of the I Ching ("Book of Changes") that Dr. Fleinhardt consults is volume 19 in the Bollingen Series, a line of books on Asian religion and philosophy published by Princeton University Press. It was translated from the original Chinese into German by Richard Wilhelm and rendered into English by Cory Baynes; the foreword was written by Dr. Carl Jung.
This is considered one of the most authoritative versions of the I Ching in English, although it is not the most popular one due to the fact that it is a straight translation and not a collection of pat answers.
The 64 hexagrams of the I Ching can be interpreted numerically in at least two different ways. First by the numbers assigned to the diagrams in the Book of Changes from 1 to 64 and second as a series of binary numbers ranging from 0-63. The binary interpretation can, in turn, be interpreted in two different ways depending on which type of line is interpreted as a 0 or a 1.
The I Ching is a Chinese oracle that uses hexagrams, figures composed of six lines of four types. They can be broken (-- --) or unbroken (-----), and each of those types can be fixed or changing. The lines are generated by random processes, with the traditional method using yarrow sticks and a more modern "quickie" method of tossing three coins. The result is one of sixty-four hexagrams which are interpreted according to the text accompanying each figure in the Book of Changes.