In view of the fact that the GSAS is in our database as a program to support or convert various file extensions, you will find here a GSAS download link. Get the software from the GSAS developer website. Before you will download the program, make sure that you not have application GSAS on your device installed yet - this will allow you to save some space on your disk.
We do not store any files with the setup of the GSAS on our server but help to find the most reliable source from where you can download the application from. By clicking on the button "More info about GSAS" you should be directed to the official website of the GSAS developer where you can download the application.
More info about GSAS