A search system

I went to the school library to borrow some books for the written homework assignments.

I searched for some reference books with a search system. When I input some keywords, a lot of books were indicated on the screen. I choice three books out of the forty. I found it very useful.

It was good to find books I had been searching for. But it was very difficult to discover books I had searched for. I didn't know where to look for. Discovering them, I had already tired. What was worse, it had got dark and it had begun to rain.

I tried to go home.