Searches Are Weird! No they're not! Bad coding style?

In David Marcus's guest post on good coding style (see here)  he reviewed a book from 1986 called  "Professional Pascal."

I wondered if it was still in print and could be bought:

1) I went to Amazon and searched all products for Professional Pascal. I got this, which is not that book.

2) I then restricted to books, and I got the same, though later on the page I got a relevant book, here.

3) I then searched for Professional Pascal on Google, and got the Amazon site for the book here.

David thought this was weird. I did not. As I put it:

A computer does something which makes no sense. This is common, hence it's not weird.

Why did the search from outside of Amazon do better than the search inside of Amazon?

Speculation

1) Search is just a really hard problem.

2) The coders at Amazon did not use good coding style. They should read the book. If they can find it.