Systems-of-Systems (SoS) are a special type of systems composed by other systems. These systems together can reach goals that they could not benefit when operating on their own. However, this emerging discipline is not consolidated yet and there is a lack of standardization in the terminology used. In this context, knowledge representation approaches can be used to support activities in the SoS field. They can also play an important role in formalizing concepts by providing a common understanding among the community and practitioners. In this technical report we present a Systematic Literature Review (SLR) conducted to identify how knowledge representation has been applied to SoS. Our results show that interoperability is the most addressed topic. We also noticed that there is a lack of formal approaches for establishing communication in the SoS field.