Thus, "PDF 21" might be a shorthand for: "I want the PDF that covers the 21-day genius protocol."
To be objective, The Einstein Factor occupies a controversial space. Mainstream cognitive science is skeptical of claims like "triple your IQ in 20 hours." IQ scores are remarkably stable after adolescence. Einstein Factor Win Wenger Pdf 21
: Practicing these techniques for just 25 hours has been shown to raise IQ by up to 20 points. Thus, "PDF 21" might be a shorthand for: