1. Differential-Difference Equations;Bellman,1963
2. Lineare D'gleichungen mit nacheilendem Argument;Myschkis,1955
3. Stability of Motion;Krasovskii,1963
4. Uniformly semi-primitive multiplicative processes;Birkhoff;Trans. Am. Math. Soc.,1962
5. Inequalities;Hardy,1952