Customizing node reference widget As you now, when we use node reference field in a data type, during inserting a content, a list is very simple and it shows only node title.

I want to know is there any way to customize the list. for example I want to add css classes to list or add additional field such as thumbnail image and other field in this widget.

Please guide me. How can I do that ?
You can create own field formatter in code. Or use field preprocess function.

But I would suggest you to render this references as view. Than you can do with field anything you want