の知識は

as for knowledge of

→ の
phrase Rare #26,357
as for knowledge of The の connects a person or subject to 知識 (knowledge), and は marks the phrase as the topic. The full meaning depends on what comes before の, such as 日本語の知識は (as for knowledge of Japanese).
JA: 日本の歴史の知識はまだ十分ではありません。
EN: My knowledge of Japanese history is still not sufficient.

この問題についての知識はかなり限られている

My knowledge of this issue is quite limited.

少しずつ私たちの英語の知識は増えていくものです

Our knowledge of English gradually grows over time.

外国語特にスペイン語の知識は不可欠です

Knowledge of foreign languages, especially Spanish, is indispensable.

そのの知識は進歩した

The child's knowledge has advanced.