@book { TheEconomicAnalysisoftheGrowthofNetworkProducts,
    title = "The Economic Analysis of the Growth of Network Products",
    author = "Zhenyu {Liu}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1086705"
}