The phrase "external sources of knowledge" is correct and usable in written English.
You can use it when you are referring to knowledge which comes from outside sources, such as books, websites, and people. For example, "John learned a lot by consulting external sources of knowledge, including tutorials he found online and conversations with experts."
They therefore depend on external sources of knowledge for information, which in many instances are inadequate, inappropriate, or obsolete.
Making use of external sources of knowledge, on the contrary, has a significant effect on productivity.
External sources of knowledge such as WordNet have been employed to help detect such cases.
This is influenced by particular features of firm ownership, organisational and management structure, internal mechanisms to diffuse knowledge and links to external sources of knowledge.
Overall, the use of specialist knowledge providers tends to complement firms' own internal innovation activities and to complement other external sources of knowledge.
The results show that only firms complementing potential and realized absorptive capacities are able to take advantage of favorable external environments by actively combining internal and external sources of knowledge.
To cope with fast-changing business environments, firms are increasingly opening up their organizational boundaries to tap into external source of knowledge.
Variables on sources of knowledge were continuous (i.e., scales) and constructed by aggregating response items within each of the five dimensions: own experience, social interaction, internal source of knowledge, external source of knowledge, and research evidence.
In addition, we find that search and integration of knowledge from different external sources of relevance to the community positively moderates knowledge contributions by lead users.
The vast literature from Science and Technology Studies identifies the numerous ways in which 'science', far from being an external source of objective knowledge, is inextricably shaped by, and shapes, wider social values, institutions and processes (e.g. Jasanoff 2004).
This distinction is important because knowledge-based economic activity tends to be subject to high degrees of uncertainty, asymmetric information and spillovers of newly created knowledge, making access to external sources of finance difficult.
