Complex sentence: Lingua Latina secundum naturae rationem explicata published in 1955, modernizing the system and changing the title in 1990 to Lingua Latin per se illustrata, that at the moment he publishes with small adjustments.
Split into simpler sentences: Lingua Latina secundum naturae rationem explicata published in 1955. In 1990 he modernized the system and changed the title to Lingua Latin per se illustrata, which was published with small adjustments.