I think the challenge here is that what is common sense for one person is complete nonsense for others. As you've seen here in the thread, many have no clue what the initials GRO even stand for, much less how to find the information, and even worse, might make up something or replace it if they think it's garbage in the file. It's always best to give as much reasonable clarification as possible so that someone else can follow your research. As others have mentioned, it's ideal that you can click on the reference and get to the specific item referenced, however, the next best thing would be to send them to the site where they can do their own search. And barring that, at least spell out what you researched, where you researched it, and give enough information so that someone can go out and search the internet and follow your line of thinking.