How to install unixodbc-dev

[CDR <venefax@gmail.com>]

When I type "apt-get install unixodbc-dev"
I get back:
"Reading package lists... Done
Building dependency tree
Reading state information... Done
Package unixodbc-dev is not available, but is referred to by another
package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'unixodbc-dev' has no installation candidate"

Question, maybe I need to add some repositories?

My /etc/apt/sources.list has:


deb cdrom:[Debian GNU/Linux 6.0.1a _Squeeze_ - Official amd64 DVD Binary-1 2011$
deb http://security.debian.org/ squeeze/updates main contrib
deb-src http://security.debian.org/ squeeze/updates main contrib
deb http://ftp.us.debian.org/debian/ squeeze-updates main contrib
deb-src http://ftp.us.debian.org/debian/ squeeze-updates main contrib
deb http://ftp.us.debian.org/debian squeeze main

I am using stable 64 bits.
Federico