Nielsen, U. creator Aldred, A. H. text Ottawa Forest Management Institute (1978?) 1978 monographic 12 p. Ponencia presentada en : International symposium on Remote Sensing for Observation and Inventary of Earth Resources and the Endangered Envirenment. Freiburg, Alemania, 1978 Bosques Inventarios Fotografía aérea 32477 971013 20220329135209.0 000033530