Website 1: History learning site
This website is reliable because it comes from the united kingdom government (.uk), has three working links, and has link where one can complain about the accuracy of the website at the bottom.
http://www.historylearningsite.co.uk/china_war.htm
http://www.historylearningsite.co.uk/china_war.htm
This website didn't go very much in depth to how the explanations of why Japan invade China, however it did say "that they were fired on by Chinese troops at the Marco Polo Bridge near Beijing"(Webiste 1). Japan was infuriated by this attack , and wanted to become a powerful nation, so they began to invade China "in July 1937"(Website 1).
Website 2: Wikipedia
The website is credible because it has the .org domain. It also has a very big works cited page in the bottom. In addition, most hyperlinks work.
http://en.wikipedia.org/wiki/Second_Sino-Japanese_War
http://en.wikipedia.org/wiki/Second_Sino-Japanese_War
The website explained how Japan already had much influence across china in the war. In their first war "China, then under the Qing Dynasty, was defeated by Japan"(Website 2). Then, the Chinese emperor Zhuyan Xueliang "quickly took over control of Manchuria"(Website 2). Japan then started to fight China and the new communist party that started fighting for the country. They started fighting in 1937.
Website 3: history.com
This website is credible because of the .uk, there are three working links, and there are other channels that support the website.
http://www.history.co.uk/study-topics/history-of-ww2/sino-japanese-war
http://www.history.co.uk/study-topics/history-of-ww2/sino-japanese-war
The website explained that China "was a divided country"(Website 3)t, and was split into a nationalist section and a communist section. This left China in a very weak position, and Japan, "eager for the vast natural resources to be found in China and seeing her obvious weakness"(Website 3) started invading China. It turned to Manchuri, and when the United Nations told Japan that it couldn't invade China, it just left the league and started to invade China in 1937.