Guhyasamājamaṇḍalavidhi online

Follow the link in the title for an input of this extremely important text. And why not repay the CTS's generosity with the Tibetan translation. (warning: not proofread and verse-numbering may not match)

Update: It has been brought to my attention by Dr. Carmen Meinert that she was unable to download the text. Everything seems to be alright from my side, so please let me know if you meet with the same difficulty.