  We introduce a new method for detection of long-range cross-correlations and
multifractality - multifractal height cross-correlation analysis (MF-HXA) -
based on scaling of qth order covariances. MF-HXA is a bivariate generalization
of the height-height correlation analysis of Barabasi & Vicsek [Barabasi, A.L.,
Vicsek, T.: Multifractality of self-affine fractals, Physical Review A 44(4),
1991]. The method can be used to analyze long-range cross-correlations and
multifractality between two simultaneously recorded series. We illustrate a
power of the method on both simulated and real-world time series.
