Identify the Document Needed to Support Each of the Following

Identify the document needed to support each of the following activities in a manufacturing organization:
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a. Placing an order for direct materials with a supplier
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b. Recording direct labor time at the beginning and end of each work shift
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c. Issuing direct materials into production
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d. Recording the costs of a specific job requiring direct materials, direct labor, and overhead
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e. Billing a customer for a completed order
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__________ f. Receiving direct materials at the shipping dock