In this paper, the internal law of delay in the secondary literature publishing process is presented. The process is demonstrated
to abide by the partial differential equation of periodical literature publishing process. A definite solution of the publishing
delay process is derived. Accordingly, the expression of average publication delay indicator based on the particular solution
is deduced. Then the problem is studied that some information of primary literatures is missed in information retrieval, and
the relationship is established between the average delay indicator and the miss ratio of primary literatures in the index
periodicals or databases. Also it is proposed that the primary literature should be used as a supplemental tool in information
retrieval to guarantee the recall ratio.