Columbia subject headings:
Contracts--Italy.
Contracts--Spain.
Impossibility of performance--Italy.
Impossibility of performance--Spain.
Rebus sic stantibus clause--Italy.
Rebus sic stantibus clause--Spain.
Harvard subject headings:
Contracts--Italy.
Contracts--Spain.
Impossibility of performance--Italy.
Impossibility of performance--Spain.
Rebus sic stantibus clause--Italy.
Rebus sic stantibus clause--Spain.
Princeton subject headings: