Use of non ASCII characters in searching: Panama and Panamá

[Pedro]

I've searched for documentation on the use of ISO-Latin in Google, but google.com doesn't provide any.

I tested both google.com and google.cl and the results were similar. I got some interesting results.

Panama = 4,430,000
Panamá = 4,450,000
+Panama = 11,500,000. Seems to match Panama and Panamá
+Panamá = 1,530,000. Seems to match Panama and Panamá

Munchen = 432,000
München = 5,910,000
+Munchen = 433,000. Seems to match only Munchen.
+München = 16,400,000. Seems to match both München and Muenchen, but not Munchen

The most striking result is that ASCII +Panama and ISO +München get a lot more results than both spellings combined. And why does Panamá get less results than Panama, and München gets more results than Munchen?

I wish this were documented.