ShapeSheet references

[Michelle]

I need to clean house on a template I am working on.  It's a big project, and I have learned a lot while working on it. (Most of it here!)  There are some shapes within that are not really needed and at the time I didn't delete them either because I wasn't sure if they were needed or because I didn't know how at the time. (Most of them I just  made "invisible", so they aren't seen but they are taking up space)

I am ready to get rid of some of these shapes, but I wonder if there is any way to determine if a shape is referenced in another's shapesheet?

TIA,
Michelle