Journal kept by David Douglas during his travels in North America 1823-1827, together with a particular description of thirty-three species of American oaks and eighteen species of Pinus, with appendices containing a list of the plants introduced by Douglas and an account of his death in 1834. Published under the direction of the Royal Horticultural Society.

Mode of access: Internet.

Fifth census of Canada, 1911.

Mode of access: Internet.