"Gewöhnliche Differentialgleichung." . . "Vibrazioni." . . "American Mathematical Society." . . . . . . . . "Differential equations of the second order with retarded argument. Some problems of the theory of vibrations of systems with retardation" . . . . "Differecial'nye uravnenija vtorogo porjadka s zapazdyvajǔšcim argumentom" . . . . . . . . . . . . "Differential equations of the second order with retarded argument; some problems of the theory of vibrations of systems with retardation"@en . "Differential equations of the second order with retarded argument; some problems of the theory of vibrations of systems with retardation" . . . "Differential equations of the second order with retarded argument" . "Differential equations of the second order with retarded argument : some problems of the theory of systems with retardation"@en . . . . . . . . . . . . "Differential equations of the second order with retarded argument : some problems of the theory of vibrations of systems with retardation" . . "Differential equations of the second order with retarded argument : some problems of theory of vibrations of systems with retardation" . . . . . . . . "Differential equations of the second order with retarded argument some problems of the theory of vibrations of systems with retardation" . . "Ecuaciones diferenciales." . . "Drgania." . . "Gewone differentiaalvergelijkingen." . . "Vibrations." . . "Mathematische fysica." . . "Vibration." . . "Równania różniczkowe z opóźnionym argumentem." . . . . "Schwingung." . . "Équations différentielles." . . "Mechanische Schwingung." . . "Theorie." . . "Equacions diferencials ordinàries" . . "Differentialgleichung." . . "Equazioni differenziali." . .