Learning content and corrections
Send the chapter page link, the section heading and a short description of the issue to [email protected]. Include a reliable curriculum reference if you have one. Please do not send private student documents or another person’s details.
Account and payments
For access or payment problems, describe what happened and include the payment reference when relevant. Never send passwords, OTPs, card numbers, bank credentials or API keys. See the refund policy for refund requests.
Review process
Content concerns are checked against the relevant source. Material corrections may update a resource or temporarily return it to draft. We cannot promise an immediate response or a particular outcome before reviewing the issue.