Demkov, I. N. (1963). Variational principles in the theory of collisions. Pergamon Press; Macmillan, New York.
Chicago Style (17th ed.) CitationDemkov, I︠U︡. N. Variational Principles in the Theory of Collisions. [Oxford]: Pergamon Press; Macmillan, New York, 1963.
MLA (9th ed.) CitationDemkov, I︠U︡. N. Variational Principles in the Theory of Collisions. Pergamon Press; Macmillan, New York, 1963.
Warning: These citations may not always be 100% accurate.