Out of the work on the Science Citation Index (SCI) has come the field of scientometrics and the ability to quantify the impact of specific papers or journals.

From this simple exercise, we learned that initially a core group of large and highly cited journals needed to be covered in the new Science Citation Index (SCI).

This paper introduced SCI (Science Citation Index)and its source Periodicals of agronomy and some points for attention of submitting papers and searching.