Complex sentence: Construction work began in 1927, under the direction of Turinese engineer Angelo Frisa and architect Enrico Del Debbio, and was finished, after a few variations, in 1932.
Split into simpler sentences: Construction work began in 1927 directed by the Turinese engineer Angelo Frisa and architect Enrico Del Debbio. The construction was completed after a few variations, in 1932.