Some of Neruda’s dog and also Tierney poetry is very difficult to understand because they are about events of World history such as the colonization of America, the Spanish Civil War, Nazi Germany and other conflicts. Neruda also references (mentions) important figures of World history. In some of his poetry Neruda tends to link historical events from different eras (periods of history) and different parts of the world into one major conflict as in his "Canto General" (1950).