HyperTextBooks are a method of sharing information on a particular subject. But the HyperTextBook format is also flexible enough to include information on related subjects. This allows the HyperTextBook to be focused, and yet be well-rounded. The HyperTextBooks released to on-line information systems generally only contain the very basic information on a subject. But one may buy updates to go to additional levels of subject matter. The cost of an additional level of information is only $15.00. To order the next level of this HyperTextBook, contact us: