Terms of Service

Effective October 11, 2026

These terms describe purchases made directly on tekbookpublishing.com. TEKBOOK Publishing is owned and operated by ARP LAB. Please read these terms and the product description before purchasing.

1. Digital books and prices

Buy Digital Download purchases the selected book edition as a PDF file. It does not include a printed book, shipping, a subscription or automatic access to future revisions. Prices are shown in US dollars. Review the total displayed at checkout before paying. Amazon purchases are separate transactions governed by Amazon’s applicable terms and the selected listing.

2. Payment and delivery

Stripe processes payments through its checkout page. A download becomes available on the TEKBOOK confirmation page after payment is confirmed. Delayed payment methods may require additional time. TEKBOOK does not currently send the PDF as an email attachment.

Download access lasts seven days from checkout creation and requires the browser used for purchase. Cookies help verify that browser. Clearing cookies, switching browsers or closing a private browsing session can interrupt access. Download and save a backup promptly. A saved PDF does not expire. Contact support if payment succeeds but delivery fails.

3. Personal-use license

Your purchase grants a non-exclusive license to read the PDF on your own devices and print it for personal use. Copyright remains with the relevant rights holders. You may not resell, distribute, publicly upload or share copies of the file, or present the content as your own. These terms do not restrict uses permitted by applicable law.

4. Download problems and refunds

For an incorrect, unusable or undelivered file, or a duplicate purchase, contact TEKBOOK Support. Include the book title, purchase email and purchase reference if available. We will review the issue and provide the correct usable file or a refund where appropriate. If we cannot provide the purchased usable file, we will refund that purchase. Verified duplicate purchases are eligible for a refund of the duplicate charge.

Change-of-mind refunds after successful delivery are not routinely offered. Nothing in these terms excludes refund rights or other remedies required by applicable law. A refunded or disputed purchase may lose further download access. Amazon order issues must be handled through Amazon.

5. Independent publications and safety

TEKBOOK books are independent publications unless expressly stated otherwise. References to manufacturers or product names do not imply endorsement or affiliation. Follow each book’s stated scope, warnings and limitations. For maintenance work, verify procedures and specifications against manufacturer documentation for your exact model. Use appropriate protective equipment and qualified professional help. A book cannot replace hands-on training or an individual assessment of equipment.

6. Website use and availability

Do not attempt unauthorized access, interfere with checkout or download services, or use the site unlawfully. Temporary outages or payment delays may occur. If an outage prevents delivery of a paid book, contact support for assistance under the refund policy above.

7. Purchase information

Payment information entered at Stripe is handled by Stripe. TEKBOOK uses purchase references, the selected book, payment status and amount, and a browser-linked cookie identifier to verify delivery. Support requests may include information you send by email. Do not email full card numbers, passwords or card security codes. Contact support with questions about your purchase information.

8. Updates and consumer rights

The terms displayed when you purchase govern that purchase. Later updates to these terms do not retroactively remove rights granted for an earlier purchase. Nothing here limits rights that cannot lawfully be excluded.

9. Contact

For purchase, download or refund questions, email TEKBOOK Support. For step-by-step instructions, see Questions & Answers.