After a while I looked him up in the phone book.

Finally, he looked up his own last name in a phone book.

We'll have to look up his name in a history book when we get back.

I looked up his private office in the phone book.

Every now and again people look up in the air.

I looked up in the trees but didn't see anyone.

I looked it up just in case- and you did ask.

She looked up the Voice itself in one of the old books.

She was standing very close to him, looking up in his face.

She couldn't simply look him up in the phone book.