Determining the embedding parameters governing long-term dynamics of copper pricesCortez, Carlos A. Tapia; Hitch, Michael William; Sammut, ClaudeChaos, solitons and fractals2018 / p. 186-197 : ill http://dx.doi.org/10.1016/j.chaos.2018.03.032 Üliõpilased uurisid elektrikaupade turguLaugis, JuhanPingering1997 / 10. juuni, lk. 2: ill