This study explores the evolving structure of the rising field of “network of networks” (NoN). Reviewing publications dating back to 1931, we describe the evolution of major NoN research themes in different scientific disciplines and the gradual emergence of an integrated field. We analyse the co-occurrence networks of keywords used in all 7818 scientific publications in Scopus database that mention NoN and other related terms (i.e., “interconnected networks”, “multilayer networks”, “multiplex networks”, “interdependent networks”, “multinetworks”, “multilevel networks”, and “multidimensional networks”). The results show that the NoN began to form as a field mainly in the 1990s around research on neural networks. Diverse aspects of NoN research, indicated by dominant keywords such as “interconnection”, “multilayer”, and “interdependence”, gradually spread to computer and physical sciences. As of 2018, network interdependence – with its application in network resilience and prevention of cascading failure – seems to be one of the key topics attracting broad academic attention. Another noteworthy observation is the emergence of a distinct cluster of terms relevant to nanoscience and nanotechnology. It is envisaged from the analysis that NoN concepts will develop stronger ties with nanoscience with increasing understanding and data acquisition from the molecular, atomic, and subatomic levels.

这项研究探索了“网络网络”（NoN）上升领域的演进结构。在回顾可追溯到1931年的出版物时，我们描述了不同科学学科中主要的NoN研究主题的演变以及集成领域的逐渐兴起。我们分析了Scopus数据库中所有7818个科学出版物中提及NoN和其他相关术语（即“互连网络”，“多层网络”，“多路网络”，“相互依赖的网络”，“多网络”）的关键字的共现网络。 ”，“多层网络”和“多维网络”）。结果表明，NoN主要在1990年代围绕神经网络的研究开始形成。NoN研究的各个方面，以“互连”，“多层”和“相互依赖”等占主导地位的关键字表示，逐渐传播到计算机和物理科学。截至2018年，网络相互依赖性及其在网络弹性和级联故障预防中的应用似乎已成为引起广泛学术关注的关键主题之一。另一个值得注意的观察是出现了一系列与纳米科学和纳米技术有关的独特术语。通过分析可以预见，随着人们对分子，原子和亚原子水平的理解和数据收集的增加，NoN概念将与纳米科学发展更牢固的联系。另一个值得注意的观察是出现了一系列与纳米科学和纳米技术有关的独特术语。通过分析可以预见，随着人们对分子，原子和亚原子水平的理解和数据收集的增加，NoN概念将与纳米科学发展更牢固的联系。另一个值得注意的观察是出现了一系列与纳米科学和纳米技术有关的独特术语。通过分析可以预见，随着人们对分子，原子和亚原子水平的理解和数据收集的增加，NoN概念将与纳米科学发展更牢固的联系。