Partitioning a sequence into few monotone subsequences - Bar-Yehuda, Reuven; Fogel, Sergio (haṭ- Ṭeḵniyyôn, Māḵôn Ṭeḵnôlôgî le-Yiśrā'ēl <Ḥêfā> / Department of Computer Science: Technical report, 1990)