The authors cannot exclude that the internet links mentioned in the references will not be changed as time passes. To the best of the authors’ knowledge the references that have been included have been given the current links, but we cannot take responsibility for the changes that may occur.

Mention of sites in this publication is not a formal recommendation, nor is it a guarantee of their accuracy. Always remember when using the web that:

Man's most judicious trait is a good sense of what not to believe