Copyright does not protect the information, data, ideas, or principles in a work. It protects the way those aspects are expressed provided that the expression is original to the work [link to test of originality]. These aspects can be used when writing your own text or creating another work provided the new work is original in its new expression of those ideas, principles and information. However, it is always good practice to acknowledge your sources.
Copyright also does not protect names, titles, slogans or phrases. These have to be protected by being registered as Trade Marks under separate legislation.