Hi Catelina, I looked on the Web for sites relating to mimetic words and onomatopoetic words. I found several sites for onomatopoeia, one of which is
http://www.tnellen.com/cybereng/lit_terms/onomatopoeia.html
If you want to look for more sites about this word, I suggest you enter the word onomatopoeia.
As for mimetic words, I'm sorry to say that not only am I not sure of what these are, but I couldn't find a site that I thought would be of help to you. Most of the discussions relate to Japanese or Korean, and the few that relate to English are written at a very high level and would probably be impossible for you to understand.
I'm sorry that I couldn't be of more help. Perhaps other a2kers will stop by this thread and offer you more advice and information.