(e) 2. A general cost estimate is approximated of each item to ascertain purchase cost group level classification prior to bid action. SELECTION OF BID SOURCES (a) A procurement library is maintained for the selection of prospective bidders and for reference use of technical nomenclature of materials. This library includes manufacturers' catalogs, distributors' sales pamphlets, manufacturers' brochures, and various groups of sales literature, and classified telephone directories of all major cities of the United States. These catalogs are shelved and segregated by material commodity classification reference. (>) A complete reference file is maintained on Atomic Energy Commission and other governmental agency surplus materials stock lists and all requisitions are screened to these lists prior to being channeled to the commercial market. (c) To reduce freight, storage, handling and shipping costs, a survey is made to find the market offering the closest loc- ation to the place of transhipment (Oakland, California) 3. BIDDING AND AWARD PROCEDURE -- PURCHASE LEVELS (a) PETTY CASH PURCHASES, PURCHASE LEVEL CLASS A (1) Scope and Limitations a, Cost limitation of materials or services shall not exceed monetary value of ten dollars ($10) for each individual purchase from any one source of supply. (2) b. Petty Cash purchases shall be limited to such items required for emergency use. It is to be further confined to the purchase of items the value of which would not warrant the cost of writing a formal purchase order. c. No competitive bidding shall be required. Authorization and Receipt a. Petty cash expenditures will be made only with the approval of the Purchasing Agent. bd. All Petty Cash expendttures shall be supported by three signed copies of the seller's sales slip and/ or invoice. One copy of the invoice to be filed in the Purchasing Department "Petty Cash Expenditures" file, chronologically by date of purchase, one copy 13-39