Figure 2.—Left, Biplot of reference disciplines by specialty of author. Right, Biplot of country in which reference was published and in what country the authors reside. The points represent reviews, and distances between points reflect differences between reviews in their citation patterns, according to discipline (left) and country (right). The axes show the direction in which the percentage of references in a reference category increase, and tick marks represent 5% increments. For example, the left side of the figure shows that reviews vary from approximately 0% references in the laboratory category to 100% from right to left.
