* [https://sinclair.zilog.fr Sinclair's Spirit (FR)] Learn how to code with Z80 Assembler on ZX Spectrum with [[BDCIron]]
* [https://problemkaputt.de/zxdocs.htm Noca$h's ZXdocs]
* [http://www.retro8bitcomputers.co.uk/Content/downloads/books/SpectrumHardwareManual_2ndEdition.pdf Spectrum Hardware Manual]* [https://pdfcoffee.com/the-zx-spectrum-ula-how-to-design-a-micro-chris-smith-pdf-free.html The ZX Spectrum ULA ebook]* [https://worldofspectrum.net/documentation/ ZX World of Spectrum documentation]* [https://www.spectrumforeveryone.com/technical/ Spectrum for Everyone] [https://sinclair.wiki.zxnet.co.uk Sinclair Wiki]* [https://www.speccy.org/ Speccy.org] El portal español del SpectrumDocumentation
* [https://worldofspectrum.net/pub/sinclair/ World of Spectrum file server]
* [https://tzxvault.org/ The TZX Vault]
* [https://www.speccy.org/ Speccy.org] El portal español del Spectrum
* [https://youtu.be/I9dHI6EwWTU Sinclair ZX Spectrum Story - Birth of a Classic] by [[Nostalgia Nerd]]
* [https://youtu.be/fTKckoSj-OE Timex Sinclair 2068 - The American ZX Spectrum] by [[The 8-Bit Guy]]