Multiple Bibliographies with Latex

I am currently working on a book which is a compilation of various articles dealing with virtualization techniques. All articles are written in Latex and have the same template in common which makes it much easier to combine them into a single document. There are about 20 articles with four to five pages each. In total there are about 150 references.

Although Latex is designed to layout large text documents such as articles, reports, and  books, I encountered some troubles in this case. The challenge was to have several separate bibliography sections, one at the end of each chapter. There are packages available to accomplish this. The first package I tried is multibib. It is easy to use and it seems to work fine. Unfortunately, after including several of my articles, latex failed to compile the document with following error message:

No room for a new write newcites{.....}

After an intensive search for solutions it turns out that this is due to an internal limitation of Tex without a solution (without changing the source code of Tex). It is a limitation of file handles and the implementation of multibib exhausts them. There is a thread ( which redefines several commands and it basically works but there are still limitations. I extended the code but finally it turned out to be too much effort.

I decided to use a different package: bibunits. And this works as expected. Thanks to Thorsten Hansen for this package.