Primary research into "bushidō" was later conducted by William Scott Wilson in his 1982 text "Ideals of the Samurai: Writings of Japanese Warriors". The writings span hundreds of years, family lineage, geography, social class and writing style—yet share a common set of values. Wilson's work also examined older Japanese writings unrelated to the warrior class: the Kojiki, Shoku Nihongi, the Kokin Wakashū and the Konjaku Monogatari, as well as the Chinese Classics (the Analects, the Great Learning, the Doctrine of the Mean, and the Mencius).