Citations: any organic chemistry textbook in the world. That article was obviously not written by someone who has taken organic chemistry. There are a number of organic (and inorganic) solvents that will extract the chemicals in cannabis. Different solvents will produce different chemical profiles (ex. the difference between butane and CO2 extractions). There are thousands of peer-reviewed journal articles detailing organic extraction methods, I am somewhat surprised that people haven't gone beyond the typical solvents currently in use. However, heat alone will simply decompose most of these compounds.