The average citation per article in chemistry by age of citation is related to the Poisson frequency distribution. This provides a formula for calculation of a half-life for chemistry which depends on the structure of the research front exhibited in the literature. (Author/FM)

The problem of forecasting monthly demands for library network services is considered in terms of using forecasts as inputs to policy analysis models, and in terms of using forecasts to aid in the making of budgeting and staffing decisions. Box-Jenkins time-series methodology, adaptive filtering, and regression approaches are examined and compared…