Please type your subject in the School Subject box. Any other words are likely to delay responses from a teacher who knows that subject well.
Since this is not my area of expertise, I searched Google under the key words "Lewis structure" to get these possible sources:
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps.