This should get you started.
SELECT
C2.Name AS Data_Source_Name,
C.Name AS Dependent_Item_Name,
C.Path AS Dependent_Item_Path
FROM ReportServer.dbo.DataSource AS DS
INNER JOIN ReportServer.dbo.Catalog AS C
ON DS.ItemID = C.ItemID AND DS.Link IN (SELECT ItemID FROM ReportServer.dbo.Catalog WHERE Type = 5)
FULL OUTER JOIN ReportServer.dbo.Catalog C2
ON DS.Link = C2.ItemID
WHERE
C2.Type = 5
ORDER BY
C2.Name ASC,
C.Name ASC;