Read the following passage from Bulfinch's Mythology: Milton alludes to the story of Proserpine in Paradise Lost, Book IV.:

"Not that fair field

Of Enna where Proserpine gathering flowers,

Herself a fairer flower, by gloomy Dis (a name for Pluto)

Was gathered, which cost Ceres all that pain."
An allusion of an original work of literature in another work of literature would be an example of which schematic connection?

text-self
text-world
text-text