When initially released, Hubbard wrote "It has always been my intention that you have full certainty on the technology of Dianetics and Scientology. it was with this intention that I began to write up the research in the beginning." The "Tech Vols" as they are known among Scientologists contain some 50 years of LRH's research into mankind, the mind and human spirit. The first thirteen volumes are organized chronologically, while the last 4 volumes contain bulletins that are part of a specific series such as the C/S Series. The final volume is an index to the entire series.