# References

Compiled references for the [History](../part1/history.md) and [Foundations](../part1/foundations.md) chapters.
Numbers `[1]`–`[6]` correspond to the eras in the History chapter. Gathered through deep research (June 2026); primary sources are cited wherever possible.

## [1] Era of Expert Systems & Knowledge Representation

1. Shortliffe, E. H. (1976). *Computer-Based Medical Consultations: MYCIN*. Elsevier/North-Holland.
2. Buchanan, B. G., & Shortliffe, E. H. (Eds.) (1984). *Rule-Based Expert Systems: The MYCIN Experiments of the Stanford Heuristic Programming Project*. Addison-Wesley.
3. Minsky, M. (1974). *A Framework for Representing Knowledge*. MIT AI Lab Memo 306.
4. Feigenbaum, E. A., Buchanan, B. G., & Lederberg, J. (1971). On Generality and Problem Solving: A Case Study Using the DENDRAL Program. *Machine Intelligence*, 6.
5. Lenat, D. B., & Guha, R. V. (1990). *Building Large Knowledge-Based Systems: Representation and Inference in the Cyc Project*. Addison-Wesley.

## [2] Era of Ontologies & the Semantic Web

6. Berners-Lee, T., Hendler, J., & Lassila, O. (2001). The Semantic Web. *Scientific American*, 284(5), 34–43. <https://www.lassila.org/publications/2001/SciAm.html>
7. Gruber, T. (1993). A Translation Approach to Portable Ontology Specifications. *Knowledge Acquisition*, 5(2).
8. W3C (1999, rev. 2004, 2014). *Resource Description Framework (RDF)*. <https://www.w3.org/RDF/>
9. W3C (2004, rev. 2009). *OWL Web Ontology Language Overview*. <https://www.w3.org/OWL/>
10. schema.org (2011). *schema.org — shared structured-data vocabulary* (Google, Bing, Yahoo). <https://schema.org/>

## [3] Era of Databases & Information Retrieval

11. Codd, E. F. (1970). A Relational Model of Data for Large Shared Data Banks. *Communications of the ACM*, 13(6), 377–387. <https://dl.acm.org/doi/10.1145/362384.362685>
12. Spärck Jones, K. (1972). A Statistical Interpretation of Term Specificity and Its Application in Retrieval. *Journal of Documentation*, 28(1), 11–21.
13. Robertson, S. E., Walker, S., Jones, S., Hancock-Beaulieu, M., & Gatford, M. (1994). Okapi at TREC-3. *Proceedings of TREC-3*.
14. Apache Software Foundation. *Apache Lucene* (Doug Cutting, 1999). <https://lucene.apache.org/>
15. Elastic (2010). *Elasticsearch* (Shay Banon). <https://www.elastic.co/>

## [4] Era of Wikis & Personal Knowledge Management

16. Cunningham, W. (1995). *WikiWikiWeb* — Portland Pattern Repository. <https://en.wikipedia.org/wiki/WikiWikiWeb>
17. Wales, J., & Sanger, L. (2001). *Wikipedia*. Wikimedia Foundation. <https://en.wikipedia.org/wiki/Wikipedia>
18. Luhmann, N. (1981). Kommunikation mit Zettelkästen. In *Öffentliche Meinung und sozialer Wandel*. <https://zettelkasten.de/introduction/>
19. Obsidian.md (2020). *About Obsidian*. <https://obsidian.md/about>

## [5] Era of AI: Embeddings, Vector Search & RAG

20. Mikolov, T., Chen, K., Corrado, G., & Dean, J. (2013). Efficient Estimation of Word Representations in Vector Space. arXiv:1301.3781. <https://arxiv.org/abs/1301.3781>
21. Singhal, A. (2012). Introducing the Knowledge Graph: things, not strings. *Google Blog*. <https://blog.google/products/search/introducing-knowledge-graph-things-not/>
22. Johnson, J., Douze, M., & Jégou, H. (2017). Billion-scale Similarity Search with GPUs (FAISS). arXiv:1702.08734. <https://arxiv.org/abs/1702.08734>
23. Devlin, J., Chang, M.-W., Lee, K., & Toutanova, K. (2018). BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding. arXiv:1810.04805 (NAACL-HLT 2019). <https://arxiv.org/abs/1810.04805>
24. Lewis, P., Perez, E., Piktus, A., et al. (2020). Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks. arXiv:2005.11401 (NeurIPS 2020). <https://arxiv.org/abs/2005.11401>
25. Cormack, G. V., Clarke, C. L. A., & Buettcher, S. (2009). Reciprocal Rank Fusion Outperforms Condorcet and Individual Rank Learning Methods. *SIGIR 2009*.

## [6] Present & Future: LLM-Wiki, OKF & Agent Memory

26. Karpathy, A. (2026). *LLM Wiki* [GitHub Gist]. <https://gist.github.com/karpathy/442a6bf555914893e9891c11519de94f>
27. McVeety, S., & Hormati, A. (2026, June 12). *How the Open Knowledge Format Can Improve Data Sharing*. Google Cloud Blog. <https://cloud.google.com/blog/products/data-analytics/how-the-open-knowledge-format-can-improve-data-sharing>
28. GoogleCloudPlatform (2026). *Open Knowledge Format — Specification & Reference Implementations* [GitHub]. <https://github.com/GoogleCloudPlatform/knowledge-catalog/tree/main/okf>
29. Packer, C., Wooders, S., Lin, K., et al. (2023). MemGPT: Towards LLMs as Operating Systems. arXiv:2310.08560. <https://arxiv.org/abs/2310.08560>

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## Reliability Notes

- **BM25 date** — The Okapi at TREC-3 paper (1994) is the primary citation, but the formula had been developing since the late 1980s; "~1994" refers to the key publication, not the first appearance.
- **OKF date** — Most secondary sources cite 12 June 2026, while the Google Cloud blog page shows 13 June (likely a timezone difference) — 12 June is used as the canonical publication date.
- **Karpathy's gist** — Sources place it between 3–4 April 2026 (X post on the 3rd, gist following on the 4th).
- The historical content is synthesised from primary sources with encyclopaedias and standards documents used as context. Readers should verify against the originals when high accuracy is required.
