Kernel Source for Knoppix CD's

[oscar]

...kernel-2.4.20-xfs is a custom kernel...kernel-2.4.20 is no the same thing

There is in synaptic (apt-get gui frontend) the option to download kernel-2.4.20-xfs -image only, not the kernel source
¿any ideas to get kernel-2.4.20-xfs-source? ¿any debian repository?

thanks