Lecture notes and practice materials, sold per session. Delivered as PDF·ZIP files; revised versions of a purchased session are free to re-download.

Purchase and delivery

Payment is processed at the Gujo checkout (hosted), so card details are never stored here. After payment, the purchase links to your Gujo account and materials download from the downloads page.

Change devices or delete files — you can always re-download from My Page.

Refunds

Refunds follow the refund policy document. See refund policy