Chikara Mizokami, Takaaki Ohnishi. Revealing Persistent Structure of International Trade by Nonnegative Matrix Factorization. In Chantal Cherifi, Hocine Cherifi, Márton Karsai, Mirco Musolesi, editors, Complex Networks & Their Applications VI - Proceedings of Complex Networks 2017 (The Sixth International Conference on Complex Networks and Their Applications), COMPLEX NETWORKS 2017, Lyon, France, November 29 - December 1, 2017. Volume 689 of Studies in Computational Intelligence, pages 1088-1099, Springer, 2017. [doi]