Here are some alternatives:
* Corpus of knowledge: This emphasizes a collection of knowledge, often with a focus on written or recorded material.
* Wellspring of knowledge: This implies a source or origin of knowledge, emphasizing its depth and abundance.
* Treasure trove of knowledge: This emphasizes the value and richness of the knowledge being referred to.
* Repository of knowledge: This highlights the storage and preservation of knowledge.
Ultimately, the best choice depends on the specific context and the nuance you want to convey.