These are the best sources of information to use in each case. For detailed, well-researched information, a book is usually your best option. However, due to the time it takes to publish them, this is only an option for information that is over two years old. On the other hand, for basic, brief information on a topic, an encyclopedia is likely to work well. Finally, if you had to speak about Vietnam veterans, it would be best if you interviewed veterans themselves.
