Information pursuant to Art. 13 GDPR on the processing of your personal data when visiting and using this website.
This is an English translation for convenience. The German original is legally binding: see the German version.
The controller responsible for data processing on this website is:
Detlef Rathmer
Molkereiweg 9 · 48727 Billerbeck, Germany
Phone: +49 2543 93 18 507
Email: detlefrathmer@t-online.de
This website is hosted via GitHub Pages, a service of GitHub, Inc. (88 Colin P. Kelly Jr. Street, San Francisco, CA 94107, USA), a subsidiary of Microsoft Corporation. When you access the site, technically necessary data is automatically collected and stored in server log files:
Processing is based on Art. 6 Para. 1 lit. f GDPR (legitimate interest in the secure and stable operation of the website). Log files are used exclusively to ensure technical operation and are deleted once no longer required for that purpose. As GitHub, Inc. is based in the USA, data may be transferred there; this is safeguarded by appropriate guarantees (including EU Standard Contractual Clauses). Further information on GitHub's privacy practices: docs.github.com.
If you contact us by email or WhatsApp, your details (name, contact information, message content) will be stored for the purpose of processing your inquiry. The legal basis is Art. 6 Para. 1 lit. b GDPR (pre-contractual measures) or Art. 6 Para. 1 lit. f GDPR (legitimate interest in responding to your inquiry). Your data will not be shared with third parties without your consent and will be deleted once no longer required for this purpose, unless statutory retention obligations apply.
For WhatsApp, the privacy policy of WhatsApp Ireland Limited additionally applies: whatsapp.com/legal/privacy-policy-eea.
If you purchase a book or product via this website, payment is processed by the payment provider Stripe. When you click a payment button, you are redirected to a secure payment page provided by Stripe (buy.stripe.com). The data required for payment (e.g. name, email address, and billing/payment details) is entered directly with Stripe and processed by Stripe. Payment card data is not collected or stored on this website.
For customers in the European Economic Area, the provider is Stripe Payments Europe, Ltd., 1 Grand Canal Street Lower, Grand Canal Dock, Dublin, Ireland; for customers in the United States, Stripe, Inc. Legal basis: Art. 6 Para. 1 lit. b GDPR (performance of the purchase contract). Further information: stripe.com/privacy.
On our English-language landing page, we use the Meta Pixel, a service of Meta Platforms Ireland Limited, 4 Grand Canal Square, Dublin 2, Ireland ("Meta"). The Meta Pixel allows us to measure the effectiveness of our advertising campaigns and to understand how visitors use our website after seeing or clicking on an ad. Meta may combine this data with other information collected via Meta's services and use it for its own advertising purposes, in accordance with Meta's Data Policy. Legal basis: Art. 6 Para. 1 lit. a GDPR (consent), where applicable via a consent banner, or Art. 6 Para. 1 lit. f GDPR (legitimate interest in effective, measurable advertising) for visitors outside the scope of consent requirements. Further information: facebook.com/privacy/policy. You can object to Meta's use of your data for advertising purposes here: facebook.com/adpreferences.
This website uses fonts from the Google Fonts service (Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland). When the page loads, a connection is established to Google's servers, transmitting your IP address. Legal basis: Art. 6 Para. 1 lit. f GDPR (legitimate interest in a consistent presentation of the website). Further information: policies.google.com/privacy.
Some pages (e.g. book presentations) embed videos via YouTube. We use exclusively YouTube's privacy-enhanced mode (youtube-nocookie.com), which only sets cookies once you actively play a video. Nonetheless, when the page loads, a connection may already be established to YouTube's servers (Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland), transmitting your IP address. Legal basis: Art. 6 Para. 1 lit. f GDPR. Further information: policies.google.com/privacy.
This website contains links to external sales platforms such as Books on Demand (BoD) and Amazon, through which individual titles can be purchased. If you follow such a link, only the privacy policy of the respective provider applies. The respective operators are solely responsible for their content and data processing.
This website itself does not set cookies and does not use its own analytics or tracking services beyond the Meta Pixel described in section 5. Some embedded services (e.g. Stripe's payment page after redirection, or YouTube once a video is actively played per section 7) may use technically necessary or functional cookies; this lies within the responsibility of the respective provider.
Regarding your personal data, you have the following rights:
To exercise your rights, please contact us by email at detlefrathmer@t-online.de. You also have the right to lodge a complaint with the competent data protection supervisory authority. For North Rhine-Westphalia, this is the State Commissioner for Data Protection and Freedom of Information (LDI NRW): www.ldi.nrw.de. If you are located in the United States or elsewhere outside the EU, you may also contact your local consumer protection or privacy authority.
Last updated: July 2026