1. Abrahamsen, P.: A review of Gaussian random fields and correlation functions. Technical report 917, Norwegian Computing Center (1997)
2. Berman, M., Diggle, P.: Estimating weighted integrals of the second-order intensity of a spatial point process. J. R. Stat. Soc. 51, 81–92 (1989)
3. Borruso, G.: Network density and the delimitation of urban areas. Trans. GIS 7(2), 177–191 (2003)
4. Bowman, A.W., Azzalini, A.: Applied Smoothing Techniques for Data Analysis. Oxford University Press, Oxford (1997)
5. Chacón, J.E., Duong, T.: Multivariate Kernel Smoothing and its Applications. CRC Press, Boca Raton (2018)