Balsiger, H., Altwegg, K., Bühler, F., Fuselier, S. A., Geiss, J., Goldstein, B. E., Goldstein, R., Huntress, W. T., Ip, W.-H., Lazarus, A. J., Meier, A., Neugebauer, M., Rettenmund, U., Rosenbauer, H., Schwenn, R., Shelley, E. G., Ungstrup, E., & Young, D. T. (1987). The composition and dynamics of cometary ions in the outer coma of Comet P/Halley. Astronomy and Astrophysics, 187, 163-168.