The PIRG campaign to make textbooks affordable is part of an international movement to protect access to knowledge. Other textbook pricing campaigns include the Access to Learning Materials in Southern Africa project. The Consumer Project on Technology (CPTech) maintains a page on a2k which links to a number of projects on a variety of international intellectual property issues associated with access to knowledge. Another concern is the high price of research journals, which have been increasingly controlled by a small cartel-like group of powerful publishers. The Public Library of Science is one example of a coordinated effort by leading researchers to create a knowledge and research base in open-source Internet-downloadable journals. The PIRG-backed TransAtlantic Consumer Dialogue, in cooperation with CPTech, has held several international conference and workshops on access to knowledge and access to medicine (information downloadable under "Other" on this page).