APA

Northern Ireland, Northern Ireland, . (1990). Giant hogweed. Belfast: Department of the Environment for Northern Ireland, Department of Agriculture for Northern Ireland.

Chicago

Northern Ireland, Northern Ireland, . 1990. Giant hogweed. Belfast: Department of the Environment for Northern Ireland, Department of Agriculture for Northern Ireland.

Harvard

Northern Ireland, Northern Ireland, . (1990). Giant hogweed. Belfast: Department of the Environment for Northern Ireland, Department of Agriculture for Northern Ireland.

MLA

Northern Ireland, Northern Ireland, . Giant hogweed. Belfast: Department of the Environment for Northern Ireland, Department of Agriculture for Northern Ireland. 1990.