Tikkanen, Matti: Long-term changes in lake and river systems in Finland. Fennia - International Journal of Geography, 2002, 180. vsk, nro 1–2, s. 31–42. Helsinki: Geographical Society of Finland. ISSN 0015-0010. Artikkelin verkkoversio (pdf). (englanniksi)
Tikkanen, Matti: Long-term changes in lake and river systems in Finland. Fennia - International Journal of Geography, 2002, 180. vsk, nro 1–2, s. 31–42. Helsinki: Geographical Society of Finland. ISSN 0015-0010. Artikkelin verkkoversio (pdf). (englanniksi)