Persons who have contributed intellectually to the article but whose contributions do not justify authorship may be named and their particular contribution described in the section 'Acknowledgements'. Such persons must give their permission to be named. A short title for use as running head as well as the full address of the author to whom correspondence should be sent are also required. Please also supply phone and fax numbers as well as your e-mail address. When essential, they are numbered consecutively and typed at the foot of the appropriate page.
Tables require a heading and figures a legend, also prepared on a separate sheet.
Due to technical reasons, figures with a screen background should not be submitted. On the back of each illustration, indicate its number, the author s name, and 'top' with a soft pencil. Color illustrations are reproduced at the author s expense. The list of references should include only those publications which are cited in the text. The surnames of the authors followed by initials should be given.