Can I install specific versions of software?

Can I install specific versions of software?

Is there a way to install older versions of software rather than the
latest version?
For example: I need PHP 5.3 and mySQL 5.1
It seems like the only option on Ubuntu is to do an apt-get php5 or mysql
- in which case it installs the latest versions of each. But that's not
the way to run an IT team. Our application was built for PHP 5.3 and mySQL
5.1 - upgrading to PHP 5.5 and mySQL 5.5 is something that has to be done
carefully with plenty of testing.
I've searched using aptitude search and I do not see anything but PHP 5.5
in there.
I have Ubuntu 13.10 Saucy Sauerkraut