These are (old, outdated) technical documents that never made it to the internet. Presumably they’re still covered by patents or other intellectual property, and they’ll hopefully be released someday. Or maybe they’re lost forever, who knows.

AMD datasheets

• AMD-751™ System Controller Data Sheet (order #21910)
• AMD Athlon™ System Bus Specification (order #21902)
• AMD Athlon™ Processor BIOS, Software, an Debug Tools Developers Guide (order #21656)

Apple databooks

• Macintosh LC Computer Developer Note