As I can see, TibetDoc is just a word processor, therefore it will still use the default Printing dialog unless it has been redesigned which I highly doubt. Load your content, go to Print and then access the Print Preferences. In the Window that will open, select double sided and use only one sheet of paper per page and continue with the printing method. Print one side, then put the paper back but reversed and the printer will continue with its print operation. Some printers will even offer an interactive window to show you have it can be done.