1. Abel, D.J., J.L. Smith (1983): A data structure and algorithm based on a linear key for a rectangle retrieval problem; Computer Vision, Graphics, and Image Processing, Vol. 24, 1–13
2. Abel, D.J., D.M. Mark (1990): A comparative analysis of some two-dimensional orderings; Intern. J. of Geographical Information Systems, Vol. 4, No. l, 21–31
3. Asano, T., A. Hasegawa, D. Ranjan, T. Roos (1993): Optimal and approximate digital halftoning algorithms and their experimental evaluation, Extended Abstract, Proc. Asian Conference on Computer Vision ACCV'93, Osaka
4. Asano, T., D. Ranjan, T. Roos (1996): Digital halftoning algorithms based on optimization criteria and their experimental evaluation, IEICE transactions on fundamentals of electronics, communications, and computer sciences, Vol. E79-A, No. 4, 1996, 524–532
5. Asano, T., D. Ranjan, T. Roos, E. Welzl, P. Widmayer (1995): Space filling curves and their use in the design of geometric data structures, Proc. 2nd Intern. Symp. of Latin American Theoretical Informatics LATIN'95, Valparaiso, Chile, 1995, to appear in TCS