For more information on how to do a Google search read:
Another reader also suggests trying to do a Google image search.
If that doesn't work, I try an advanced Ebay search. Google does search Ebay - but is sometimes misses a listing. There is a trick to search for sewing patterns on ebay. You have to enter the pattern company and number and then check the box labeled Search title and description. If the item is on ebay, you should be able to find it that way.
Ebay has a feature for buyers called I Want It Now. You can put your wish list there. I would suggest you not only tell the sellers what pattern company, and number you want. Also include what it is a pattern of and what size you are looking for.
Still can't find what you are looking for?
You might trying reading the following articles:
Locating Discontinued Patterns it contains information on how to contact the major sewing pattern companies. The "Big 4" (Butterick, Simplicity, McCall's, and Vogue) are selling their discontinued patterns on their websites.
You can also look at my related links page - I have tried to list all the vintage sewing pattern sources that I know about!