Attributions are stored in Attributions.txt file. Note the file exists in two places: origam\frontend-html\public\Attributions.txt and origam\backend\OrigamArchitect\Attributions.txt. This should not be a big problem because the file is generated and copied to both locations by a tool. See below for more details.
Architect
The attributions can be viewed in Architect by clicking on Help -> About... -> Attributions
Client
And in html client application by cliking on the user name in the top right corner and then About -> Copyright attributions
How to Genarate the Attributions
The Attributions.txt file can be generated with this utility program:
See README.md for details.