Cross-chain Smart Contract Invocations - a Multi-vocal Literature Review Protocol

This document introduces the protocol that describes how a Multivocal Literature Review (MLR) regarding Cross-chain Smart Contract Invocation (CCSCI) was planned to be conducted. The main purpose of having this protocol is to avoid bias when selecting primary sources and processing them. Furthermore, it helped co-authors gain an overview of the topic and refine the planned research methods before the actual MLR started.