Acquisition Sources:

As mentioned earlier, supply is another basic factor. Supply means availability of periodicals / serials for acquisition. Information regarding supply can be collected in the forms of various selectional sources or tools. A detailed discussion on a variety of selection tools, their characteristics, value and importance for selection of periodicals / serials is given in Unit 6 under sec. Selection Tools. 

The selection tools which should be a pad of periodicals collection of directories; lists brought out  by major indexing and abstracting services like Chemical Abstracts, Science  Citation Index, Engineering Index; trade  catalogues issued by individual publishers; current issues of important book trade journals; previews and announcements issued by publishers; union catalogues of periodicals; National Bibliographies; Reports of citation studies and Reports of User Need Surveys. 

Allocating Funds:

The selection of periodicals should also be governed by financial considerations. The finance available for periodicals will  normally be  decided by the library budget. Proper budgeting should take into account the amount needed to continue current subscriptions as  well  as the price increases  which are not unusual in the case of periodicals. The amount set apart for the latter will have to be added every year. The selection of every new item is a commitment not only for the current year but also for succeeding years.