Technical Documentation - Instructions for building your own URLs
All viewer URLs should use the path http://docs.google.com/viewer . This path accepts two parameters:
url : The URL of the document to view. This should be URL-encoded.
embedded : If set to true , the viewer will use an embedded mode interface.
For example, if you wanted to view the PDF at the URL http://research.google.com/archive/bigtable-osdi06.pdf , you would use the URL: http://docs.google.com/viewer?url=http%3A%2F%2Fresearch.google.com%2Farchive%2Fbigtable-osdi06.pdf