I want to know the answer to the following question:
When was L'Écho des savanes begun?
All the background I'm provided with is that "Adult-oriented and experimental comics flourished in the 1970s, such as in the experimental science fiction of Mœbius and others in Métal hurlant, even mainstream publishers took to publishing prestige-format adult comics.". Is that enough to answer the question?
Answer: no