You may also wish to search for items by Eklund, R. and Eklund.
Only one matching reference was found.
Gerster, J.A.; Gorton, J.A.; Eklund, R.-B., Selective solvents for separation of n-pentane from 1-pentane by extractive distillation, J. Chem. Eng. Data, 1960, 5, 423-429. [all data]