Madison, D. R., Zhu, X., Hobbs, G., Coles, W., Shannon, R. M., Wang, J. B., Tiburzi, C., Manchester, R. N., Bailes, M., Bhat, N. D. R., Burke-Spolaor, S., Dai, S., Dempsey, J., Keith, M., Kerr, M., Lasky, P., Levin, Y., Osłowski, S., Ravi, V., Reardon, D., Rosado, P., Spiewak, R., van Straten, W., Toomey, L., Wen, L., & You, X. (2016). versatile directional searches for gravitational waves with Pulsar Timing Arrays. Monthly notices of the Royal Astronomical Society, 455(4), 3662–3673. http://access.bl.uk/ark:/81055/vdc_100174257416.0x000036