Title: Yŏhaeng-gwa kaehyŏk, kŭrigo 18 segi Chosŏn ŭi kwahak kisul
Subjects: Science, History, Technology, Technological innovations, Philosophy, Sciences, Histoire, Technologie, Innovations, Philosophie
Places: Korea (South), Corée du Sud
Time periods: 18th century, 18e siècle