Author's e-mail address 6. References Footnotes should be placed at the bottom of the page to which they refer and should be divided from the text by a horizontal line 2 cm long. They must be inside the typing area. Good reproduction is achieved only when the lines are drawn very carefully. Figures are to be numbered consecutively.
Tables are to be numbered separately from the illustrations.
Each table should have a short title. Formulas should be numbered consecutively on the right-hand side of the page. Whenever possible, please update all references to papers accepted for publication, preprints or technical reports, giving the exact name of the journal, as well as the volume, first and last page numbers and year, if the article has already been published or accepted for publication. Introduction to the theory of nonlinear optimization, 2nd edn. Springer, Berlin Heidelberg New York 3.