[NTG-context] Asking for Hans Hagen candle's source code

Dear Sirs, If I can, where can I have access to show-gra.pdf source code (.tex file)? I would like to reproduce the Hans Hagen candle with the propose of illustration a "flame test" chemistry activity. Each salt burned have a different flame color and I would like to use Hans candle's with a different flame colors. Thanks a lot, have a nice day Jorge