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Sales
Bundles and the signed-copy sale
Two bundles with clear prices, free shipping on two or more copies, and a countdown to the end of the signed-copy sale. Buyers see right away what they get and what they’ll pay.
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Checkout
Checkout without an account
Parcel lockers picked on a map, invoice details pulled from the GUS REGON register once the buyer enters a Tax ID (NIP), and payment by BLIK, card, or bank transfer. If one payment gateway stops responding, the store switches to the other automatically.
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Contents
The full table of contents
A chapter list with page numbers, divided into parts. Buyers know what’s in the 464-page book before they order.
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Inside
Inside the book
Spreads showing real pages from the book: drawings, tables, and worked examples with numbers. Buyers can judge the content before they buy.
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Channel
Videos and stats from YouTube
The author’s most popular videos with their view counts. Channel stats update automatically, even when the rest of the page is served from cache.
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Questions
Answers before purchase
Answers to the most common questions about the book, shipping, and returns, so buyers don’t need to contact the seller before they order.

















