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Periodic and quasiperiodic solutions of abstract diffeгential equations. An. Sti. Univ. "Al. I. Cuza" Iaşi Sect. I a Mat. 28 (1982), 103-108.
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Time periodic solutions of a one -dimensional two-face Stefan problem. Annali di Matematica pura ed applicata (IV), 127 (1981), 67-78.
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