Xia, Z., Wang, S., Li, Y., Jiang, L., Sun, H., Zhu, S., et al. (2013). Vertically oriented polypyrrole nanowire arrays on Pd-plated Nafion® membrane and its application in direct methanol fuel cells. Journal of Materials Chemistry A, 1(3), 491-494. doi:10.1039/C2TA00914E.