在英文中，通常在开头就直接写“This is to certify that .....”或“It is hereby certified that......”,即为“特此证明”之意。
原谅我的英文也不好。。。只知道最后一句

I hereby certify that retrieval of knowledge in the performance of the race good谷歌翻译的

I have wongderful performance during competition in the literature search of knowledge,   hereby certify.

要是写简历或者别的材料，可以这样说：I had excellent performance during the knowledge contest of document retrival, hereby prove.
也可以简单地说:Excellent performance during the knowledge contest of document retrival, hereby prove，

I have an excellent performance on knowledge contest of literature search, which is hereby certified.