How to increase space between bibliography without using biblatex

Question

Is there a way to increase space between bibliography without using biblatex?

Answer 1

If you mean the space between the various references (\bibitems) this can be done as follows using etoolbox to patch the \thebibliography command.

In normal styles the bibliography is just a list, but the parameters of the list are given when the bibliography is called (\begin{bibliography} which calls \thebibliography).

\usepackage{etoolbox}
\apptocmd{\thebibliography}{\setlength{\itemsep}{18pt}}{}{}

The same idea can be used for other parameters of the list implementing the bibliography.

An alternative is to use natbib which provides \bibsep (\setlength{\bibsep}{18pt}) to change the vertical space between references.

\usepackage{natbib}
\setlength{\bibsep}{18pt}

PS replace 18pt with the measure you want.