1949-1952. 水産物分布図 fishery products map by South Korea Govt.

Quote from:Chaamiey's Japan-Korea historical records posted on 25NOV2012, titled "The South Korea Govt Document which describes "Japan Sea" on Korean Goverment."
(「日本海」と書いた韓国政府の資料)

http://blogs.yahoo.co.jp/chaamiey/55148816.html#55148816

 

Open Dong-A Ilbo degital archives
http://www.donga.com/news/d_story/politics/K_J_agreement65/data.html

Then choose the link titled

 한국의 어업보호정책:평화선 선포,1949-52　(The Fishery protectoin policy by South Korea govt; "Peace line" declaration 1949-52 and the document number :04580132 which describes the name of Japan Sea(日本海）

Although document No.04580007 and 04580072 dercribes East Sea(Sea of Japan), Korea recognizes the Japan Sea is international standard name and Dong-hae/East Sea is just a Korean-only domestic names because they use the name of Sea of Japan those maps.