There are certain journals styles that will list all authors in the bibliography. However, Endnote doesn’t allow you to search for a bibliography style that displays all authors. It only gives you the option to create a whole new style to do that, or to edit an existing style to do that. That’s a serious problem, and I have seen many blogs in which people are frustrated by that, but no solution is ever offered. Endnote is not responsible for styles, but it is absolutely responsible for having a reasonable search function for finding a style that you need. That needs to be fixed.