I recently rediscovered the library.
Clearly, I've known for many years there are libraries and that I can go to one and borrow books or CDs. But until last month, I hadn't checked out a book in probably 15 years.
And now I have about 10 books checked out. Stuff I took off my Amazon wish list. Stuff I want to read but not own. Stuff I want to browse but not read.
I tell friends about the library and they laugh. They, too, know it exists and have probably all been using its resources while I stayed away.
To lead effectively, you don't have to always use what's new. You can try what's proven and what works for others and see if you get the results you're after.
Don't worry if something is new or if something is borrowed. Just find what you need and put it to work.