Oscillation of first order linear differential equations with several non-monotone delays

Consider the rst-order linear dierential equation with several retarded arguments
x0(t) +
Xn
k=1
pk(t)x(k(t)) = 0, t  t0,
where the functions pk , k 2 C([t0,1), R+), k(t) < t for t  t0 and limt!1 k(t) = 1, for every k = 1, 2, . . . , n.
Oscillation conditions which essentially improve known results in the literature are established. An example
illustrating the results is given.