Analysis of information sources in references of the Wikipedia article "Ministry of Foreign Affairs (Thailand)" in English language version.
[T]he capital [is] called Si-a-Yuthia, (pronounced See-ah-you-té-ah....)
The eventful forty-two year reign of King Chulalongkorn of Thailand (1868–1910) was a landmark in Thai history. It was the period that Thailand began to develop herself into a modern state, with the abolition of extrality (extraterritoriality), the negotiations of treaties, the reform of law and judicial administration, and the reorganization of governmental agencies. The achievement of these aims was, in fact, partly due to the work of the "foreign advisers" who shared roles in the affairs of this small Asian country.
