Welburn, T. (1983). Advanced structured COBOL: Batch, on-line, and data-base concepts.
Chicago-viite (17. p.)Welburn, Tyler. Advanced Structured COBOL: Batch, On-line, and Data-base Concepts. 1983.
MLA-viite (9. p.)Welburn, Tyler. Advanced Structured COBOL: Batch, On-line, and Data-base Concepts. 1983.
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