Hedera helix
- Information and photographs of the leaves and flowers of Ivy.
- http://www.plant-identification.co.uk/skye/araliaceae/hedera-helix.htm

Combating the "Ivy Desert"
- Paper about the invasion of Hedera helix (English Ivy) in the Pacific Northwest, United States.
- http://horticulture.coafes.umn.edu/vd/h5015/00papers/okerman.htm

Poisonous Plants: Hedera helix
- Description and images from Poisonous Plants of North Carolina.
- http://www.ces.ncsu.edu/depts/hort/consumer/poison/Hederhe.htm

Hedera helix Fact Sheet
- Description and images.
- http://www.cnr.vt.edu/dendro/dendrology/syllabus/hhelix.htm

Ivy Removal Project (No Ivy League)
- Project to eradicate the invasive exotic Hedera helix from Forest Park, Portland, Oregon. Information on English Ivy and how to eradicate it.
- http://www.noivyleague.com/

English Ivy (Hedera helix)
- Description, images, invasiveness in the USA, and control.
- http://www.nps.gov/plants/alien/fact/hehe1.htm