Ferdinand von Richthofen (1833-1905), German geologist and explorer who published a major foundational study of the geology of China in 1887 and first introduced the term Silk Road 丝绸之路
"Duke Li of Wei Answering Emperor Taizong of Tang", military treatise attributed to Li Jing 李靖[lǐ jìng] and one of the Seven Military Classics of ancient China 武经七书[wǔ jīng qī shū]
1.lit. don't tie your shoelaces in a melon patch, and don't adjust your hat under a plum tree (idiom)2.fig. don't do anything that might arouse suspicion3.innocent acts may be misconstrued