个人作者、团体作者和出版物都是很重要的情报（发射）源。研究情报（发射）源的数量分布、方向分布、质量分布等问题是情报源研究的一类重要课题。1926年6月19日，美国一家人寿保险公司的统计员洛特卡，在《华盛顿科学院杂志》上发表了题为“科学生产率的频率分布”的论文，研究 Individual authors, group authors and publications are all very important sources of intelligence (launches). The research on the number distribution, direction distribution and mass distribution of intelligence (launch) sources is an important issue in the research of intelligence sources. On June 19, 1926, Lotka, the statistician of a life insurance company in the United States, published a paper entitled “Frequency Distribution of Scientific Productivity” in the Washington Academy of Science,