Transactios for data sources in BW 3.5

Hi experts,

I have always worked with sap BIW 7.0.

Now i'm on a project wich version is 3.5, and i cannot find the place to create data sources. Wich transaction manages it here??

And if someone has any link for differences between 7.0 and 3.5 it would be also be useful....

¡¡Thanks!!

Artur