“…Kai et al (2011) studied semiparametric CQR estimates for the semiparametric varying-coefficient partially linear model. For other references about CQR method see Tang et al (2012Tang et al ( , 2015, Jiang et al ( , 2013Jiang et al ( , 2014Jiang et al ( , 2015Jiang et al ( , 2016aJiang et al ( , 2016bJiang et al ( , 2018, Ning and Tang (2014), Zhang et al (2016), Tian et al (2016), and so on. These nice theoretical properties of CQR in linear regression motivate us to consider CQR method for massive datasets.…”