MONTREAL _ Academics hired by the tobacco industry to paint a historical portrait of how much the public knew about the harmful effects of tobacco use left out an important element, according to a witness at a class-action trial: internal documents from the companies themselves.

Robert Proctor is testifying for the plaintiffs before the Quebec Superior Court at a landmark $27 billion lawsuit that pits an estimated 1.8 million Quebecers against the country's three major tobacco manufacturers _ Imperial Tobacco Canada Ltd.; Rothmans, Benson & Hedges; and JTI-Macdonald.

Proctor, a historian from California's Stanford University, is a self-described cigarette historian and public-health advocate. He has published extensively on the history of smoking, tobacco and health....