Outline literature retrieval in poison control.

As for the systems to choose, we would advocate to start with only one, in order to learn perfectly a first retrieval language. TOXLINE, at the time being, is probably the best choice. EXCERPTA MEDICA, on the other hand, if it can be made more up-to-date, could become a very important competitor. As for the most recent literature, SCISEARCH is likely to remain unbeatable.