On stability of constant laplace solutions of the unrestricted three-body problem : PMM vol. 42, no. 6, 1978, pp. 1026–1032

It is shown that in the absence of third order resonances [1] Laplace solutions retain stability in the second order within the limits of the Routh —Joukowski necessary conditions of stability. When third order resonances and their interaction take place in a system, the question of stability in the second order and that of Liapunov instability is completely solved by the present investigation in conjunction with that in [2].