The fax and e-mail numbers of the corresponding author. Abbreviations must be explained at first mention. The Abstract should not exceed 300 words. Immediately following the Abstract no more than 5 key words are to be supplied for subject indexing. All references cited in the text, but only those, are to be listed at the end of the paper in alphabetical order under the first author's name.
Chronological order is used for more than one work by the same author or team of authors.
Works by two authors should also be listed alphabetically according to the second author's name. Journal titles should be abbreviated according to Index medicus. When styling references, the following examples should be followed. Weak associations in occupational epidemiology and the criteria for deducing causality. Springer, Berlin Heidelberg New York, pp Citations in the text should either be by numerals in square brackets referring to an alphabetically ordered, numbered list, or by author and date in parentheses.