It should work if you have the Sparrow project as a sub-project of your current project. Are the Sparrow files directly linked into your current file instead?
If you have Sparrow project nested as a sub-project, you should be able to do it as Daniel suggested:
Or you can open up the Sparrow project directly and access it there:
Also, whether you are linking the Sparrow project or the files directly, the header should be added to Build Phases -> Headers:
Last but not least, if "#import <Sparrow/SPDisplayObjectContainer_Internal.h>" is not working, try:
#import "SPDisplayObjectContainer_Internal.h"
(Vice versa)
