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If a citation, a source or a page here does not match what it should, say so. Every report is read, and confirmed corrections are made in the book and on the site. Questions about billing or a plan come here too: choose “Billing, a plan or my account”.
Reports are stored in Google Cloud with the time, your browser's user agent string, and your email address. The address is optional, except for a billing, plan or account question, which needs the email on your account so we can reply. They are used only to investigate and correct the book and the site, or to answer your question. See Privacy.