Question: What Italian pop music duo stared in the 1968 film L'oro del mondo directed by Aldo Grimaldi?

Context paragraphs:
Il ragazzo che sorride: Il ragazzo che sorride (Italian for "The boy who smiles") is a 1969 Italian musicarello film directed by Aldo Grimaldi and starring Al Bano and Susanna Martinková.

Golpes Bajos: Golpes Bajos was a 1980s pop group in Spain, a part of the so-called ""Edad de Oro del Pop Español"", i.e. "The Golden Age of Spanish Pop Music".  They were active in 1982–1986, with a final reunion tour in 1997–1998.

Beautiful but Dangerous: Beautiful But Dangerous (also released as "La donna più bella del mondo"/ "The World's Most Beautiful Woman") is a 1956 French-Italian drama film directed by Robert Z. Leonard.  The movie was a co-production between Italy (where it was released as La donna più bella del mondo) and France (where is known with the title La belle des belles).  For this film Gina Lollobrigida was awarded with a David di Donatello for Best Actress.

W le donne: W le donne (i.e. "Hurrah for the women") is a 1970 Italian musicarello film directed by Aldo Grimaldi and starring Little Tony.

Champagne in paradiso: Champagne in paradiso (Italian for 'Champagne in Paradise') is a 1984 Italian musicarello film directed by Aldo Grimaldi and starring Al Bano and Romina Power.  It is the last film of the couple.

Al Bano and Romina Power: Al Bano and Romina Power are an Italian pop music duo formed in 1975 by then-married couple Albano Carrisi and Romina Power.  They were highly successful in Italy and mainland Europe throughout the 1980s and the early 1990s.  Their best known international hits include "Felicità", "Sharazan", "Tu, soltanto tu (Mi hai fatto innamorare)", "Ci sarà", "Sempre sempre", and "Libertà!" .  The duo primarily recorded in Italian but have also released a great number of records in Spanish and French.  They participated twice in Eurovision Song Contest to a moderate success and performed five times at Sanremo Music Festival, winning in 1984 with the song "Ci sarà".  The couple also shot seven films, based on their songs, between 1967 and 1984.  The two separated and divorced in 1999, but reunited professionally in 2013.

Paths of War: Paths of War (Italian: Franco e Ciccio sul sentiero di guerra ) is a 1970 Italian western-comedy film directed by Aldo Grimaldi.

Pensando a te: Pensando a te (Italian for 'Thinking of you') is a 1969 Italian musicarello film directed by Aldo Grimaldi and starring Al Bano and Romina Power.

L'oro del mondo: L'oro del mondo (Italian for "The gold of the world") is a 1968 Italian musicarello film directed by Aldo Grimaldi and starring Al Bano and Romina Power.

Cindy's Love Games: Amanti miei (literally: "My Lovers", internationally released as Cindy's Love Games, "Tight Fit" and "Barbara's Escapades") is a 1979 Italian commedia sexy all'italiana film directed by Aldo Grimaldi.

Supporting paragraphs: L'oro del mondo Al Bano and Romina Power
Answer: Al Bano and Romina Power