Table 3.

Top 20 keywords in the seven periods.

First period (1949–1958)	Second period (1959–1968)	Third period (1969–1978)	Fourth period (1979–1988)	Fifth period (1989–1998)	Sixth period (1999–2008)	Seventh period (2009–2018)
Mao	Mao	Mao	Socialism	Hong	Development	Development
Soviet	Imperialism	Cambodia	Reform	Kong	Sides	International
Burma	Shek	Samdech	Hong	Development	International	Economic
Chiang	Chiang	Health	Kong	Economic	Mutual	Global
Shek	Kai	Indochinese	Socialist	World	Economic	Mutual
Imperialists	Japanese	Aggression	Mao	Sino-	Republic	security
War	Struggle	Nixon	Plenary	Reunification	EU	Sides
Kai	Japan	Sihanouk	Revolution	International	Exchanges	Exchanges
Union	Montgomery	Samdech Penn Nouth	Productive	Compatriots	Strengthen	ASEAN
Comrade	War	Norodom	Policies	Stability	Security	Promote
Stalin	Imperialists	Imperialism	Zedong	Motherland	Bilateral	Regional
Aggression	Vietnam	Cambodian	Mistakes	Straits	Promote	Africa
Korea	Troops	national	Policy	Developing	Stability	Growth
Kuomintang	Revolution	Modernizations	Principles	Socialism	Dialog	Efforts
Diplomatic	Snow	Japan	Modernization	Need	ASEM	Sustainable
Burmese	American	Zedong	Party	Defense	Regional	EU
Imperialist	Latin	Penn	Economy	HKSAR	Developing	Stability
Sukarno	Africa	Struggle	Years	APEC	SCO	Dialog
Zhou	Not	Normalization	Modernizations	Socialist	Efforts	Strengthen
Imperialism	Imperialist	Japanese	Shall	Rights	APEC	Bilateral