[en] Angular correlation measurements were made on gamma-ray cascades in ¹⁴⁰Ba, ⁹⁰Sr, and ¹⁴⁰Cs. These fission-product activities were isobarically enhanced from Kr and Xe noble-gas parents, which were mass-separated by the TRISTAN isotope separator system. Levels in ¹⁴⁰Ba were populated from the 64-sec decay of ¹⁴⁰Cs, and in ¹⁴⁰Cs from the 14-sec decay of ¹⁴⁰Xe. Levels in ⁹⁰Sr were populated from the 2.7-min decay of ⁹⁰Rb, which was populated from the decay of ⁹⁰Kr. The most intense transitions were measured in coincidence with the first excited state to ground state transition in even-even ¹⁴⁰Ba and ⁹⁰Sr. The two-parameter mode of data accumulation was used to study cascades with transitions in coincidence with the 806-keV and 989-keV transitions in odd-odd ¹⁴⁰Cs. In the study of cascades in ¹⁴⁰Ba definite spin assignments were made for eight levels, and tentative spin assignments for five levels. For ⁹⁰Sr definite spin assignments were made for eight levels, and tentative assignments for six levels. A definite 1- spin-parity assignment was made for the 103-keV level in ¹⁴⁰Cs, and tentative assignments were made for five other levels. Values are given for the angular correlation coefficients, and limits of multipolarity mixing ratios are given where applicable. (44 figures, 3 tables) (U.S.)