Mamienko, Sergey; Mieshkov, V.I.; Zuyenok, I.І. (Видавництво НГУ, 2017)
According to eMarketer researchers, the total number of smartphones in active
use on the planet exceeded the 2 billion unit in 2016 and amounted up to 2.16 billion
against 1.9 billion in 2015 and 1.6 billion devices in ...