Daniel, J. W. (1971). The approximate minimization of functionals. Prentice-Hall.
Citazione stile Chigago Style (17a edizione)Daniel, James W. The Approximate Minimization of Functionals. Englewood Cliffs: Prentice-Hall, 1971.
Citatione MLA (9a ed.)Daniel, James W. The Approximate Minimization of Functionals. Prentice-Hall, 1971.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.