References

Compiled references for the History and Foundations 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

  1. 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
  2. Gruber, T. (1993). A Translation Approach to Portable Ontology Specifications. Knowledge Acquisition, 5(2).
  3. W3C (1999, rev. 2004, 2014). Resource Description Framework (RDF). https://www.w3.org/RDF/
  4. W3C (2004, rev. 2009). OWL Web Ontology Language Overview. https://www.w3.org/OWL/
  5. schema.org (2011). schema.org — shared structured-data vocabulary (Google, Bing, Yahoo). https://schema.org/

[3] Era of Databases & Information Retrieval

  1. 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
  2. Spärck Jones, K. (1972). A Statistical Interpretation of Term Specificity and Its Application in Retrieval. Journal of Documentation, 28(1), 11–21.
  3. Robertson, S. E., Walker, S., Jones, S., Hancock-Beaulieu, M., & Gatford, M. (1994). Okapi at TREC-3. Proceedings of TREC-3.
  4. Apache Software Foundation. Apache Lucene (Doug Cutting, 1999). https://lucene.apache.org/
  5. Elastic (2010). Elasticsearch (Shay Banon). https://www.elastic.co/

[4] Era of Wikis & Personal Knowledge Management

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

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

  1. 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
  2. Singhal, A. (2012). Introducing the Knowledge Graph: things, not strings. Google Blog. https://blog.google/products/search/introducing-knowledge-graph-things-not/
  3. Johnson, J., Douze, M., & Jégou, H. (2017). Billion-scale Similarity Search with GPUs (FAISS). arXiv:1702.08734. https://arxiv.org/abs/1702.08734
  4. 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
  5. 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
  6. 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

  1. Karpathy, A. (2026). LLM Wiki [GitHub Gist]. https://gist.github.com/karpathy/442a6bf555914893e9891c11519de94f
  2. 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
  3. GoogleCloudPlatform (2026). Open Knowledge Format — Specification & Reference Implementations [GitHub]. https://github.com/GoogleCloudPlatform/knowledge-catalog/tree/main/okf
  4. Packer, C., Wooders, S., Lin, K., et al. (2023). MemGPT: Towards LLMs as Operating Systems. arXiv:2310.08560. https://arxiv.org/abs/2310.08560

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.