Which are the 5 main books …

The famous books of Carl Linnaeus are Systema Naturae (Published in 1758) and Species Planatareium (in 1753).

In 1735, he wrote his ideas down in Systema Naturae.
In it, he grouped together animals and plants with similar traits. These included similarities of body parts, size, shape, and methods of getting food.
The book went through many editions. The most important one was the 10th edition. He published it in 1758-1759.
The title was "Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis".
In English, the title would be "The system of nature through the three kingdoms of nature, according to classes, orders, genera and species, with characters, differences, synonyms, places"
Linnaeus based his classification on 5 levels: kingdom, class, order, genus, and species.
His work became the foundation for modern biological nomenclature.