APA (7th ed.) Citation

Bleeker, P., McAlpine, J. R., & Keig, G. (1984). Soil resources, demography and land use: An example of steep-land problems in Papua New Guinea.

Chicago Style (17th ed.) Citation

Bleeker, P., J. R. McAlpine, and Gael Keig. Soil Resources, Demography and Land Use: An Example of Steep-land Problems in Papua New Guinea. 1984.

MLA (9th ed.) Citation

Bleeker, P., et al. Soil Resources, Demography and Land Use: An Example of Steep-land Problems in Papua New Guinea. 1984.