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                                GOST
                             | 
                            Lerner V., Portugal V. Economic-mathematical model of productional structures optimal amalgamation // Economics and the Mathematical Methods.  – 1991. – V. 27. – Issue 5 C. 979-981 .  | 
                        
                                                                    
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                                MLA
                             | 
                            Lerner, V., Portugal, Victor "Economic-mathematical model of productional structures optimal amalgamation." Economics and the Mathematical Methods.  27.5 (1991).:979-981.  | 
                        
                                                                    
                            | 
                                APA
                             | 
                            Lerner V., Portugal V. (1991). Economic-mathematical model of productional structures optimal amalgamation.  Economics and the Mathematical Methods.  vol. 27, no. 5, pp.979-981  |