It is for this reason that the local technical and consumer press is so valuable. By itself, it will provide most of that information, but even if not, it will give leads to more suitable sources such as government departments or trade associations. All sources produced outside the target country should be treated with great circumspection. Their main use is to provide leads to more authoritative sources. These considerations apply not only to written material, but also to oral information.
Oral information can often be very partial and out of date.
Always try to cross-check anything gained from one source against another. Perfect accuracy is unobtainable, but it is surprising how much structured study reveals. The methods outlined in this article have their limits. They were developed for and are best suited for comparing countries with a similar cultural background and state of economic development, e.g. developed Western countries. However, the principles can be adapted for other cultural areas such as the South East Asian and Islamic.