Specifically for Korea, the major event that has attracted most attention is Hideyoshi's invasion, 1592-1598. The resources resulting from that attention amount to 3 major books, and various journal articles and other books. Two of these books are in the reading list (but in the Imperial China section of the list):

• The Imjin War: Japan's Sixteenth-Century Invasion of Korea and Attempt to Conquer China by Samuel Hawley (2005). One of the three main English accounts of the Imjin War, perhaps the only thing that comes close to a "world war" in East Asia. This is not the most comprehensive text on the war but it gives an excellent introduction. Hawley uses mostly Korean sources for this book and writes from a Korean perspective, so the book does suffer from a pro-Korean bias.

• A Dragon's Head and a Serpent's Tail: Ming China and the First Great East Asian War, 1592–1598 by Kenneth M. Swope (2009). The newest of the three books, Swope writes from a Chinese perspective and uses a lot of Chinese primary sources. Though his text has been criticized for providing flawed information, as a military historian, Swope gives an excellent account of the capabilities of the Ming military. It is best to read Hawley, Turnbull, and Swope together.

The third book, referred to in the comments on Swope above, but not in the list, is

• Stephen Turnbull, Samurai Invasion: Japan's Korean War 1592-1598, Cassell, 2002. Turnbull depends on Japanese sources, Swope on Chinese sources, and Hawley on Korean sources. It's good to read all three.

Also useful is

• Peter H. Lee (ed), Record of the Black Dragon Year, Univ of Hawaii Pr, 2000. This is a translation of a contemporary Korean popular history of the war.

Two books that cover the modernisation of the Korean army as a result of the Japanese invasion in the context of wider changes in East Asian warfare c. 1600 are:

• Peter A. Lorge, The Asian Military Revolution: From Gunpowder to the Bomb, Cambridge University Press, 2008.

• Tonio Andrade, The Gunpowder Age: China, Military Innovation, and the Rise of the West in World History, Princeton University Press, 2016.

See also

• Tonio Andrade, Hyeok Hweon Kang, Kirsten Cooper, "A Korean Military Revolution? Parallel Military Innovations in East Asia and Europe", Journal of World History 25(1), 51-84 (2014)

There are also some sources on the US war in 1871:

• Gordon H. Chang, "Whose "Barbarism"? Whose "Treachery"? Race and Civilization in the Unknown United States-Korea War of 1871," Journal of American History 89(4) 1331-1365 (2003)

• Carolyn A. Tyson, "Marine Amphibious Landing in Korea, 1871", http://webarchive.loc.gov/all/20100407175236/http%3A//www.history.navy.mil/library/online/marine_amphib_korea.htm

Some sources on weapons and armour:

• Sang H. Kin (trans), Muye Dobo Tongji: Comprehensive Illustrated Manual of Martial Arts of Ancient Korea, Turtle Press, 2000. Translation of a late 18th century Korean military manual.

• Boots, J. L., "Korean Weapons and Armour", Trans. Korean Branch Royal Asiatic Society, XXIII, Pt. 2, pp. 1-37 (1934). http://www.raskb.com/content/full-texts-volume