MATHEMATICAL MODELING AND COMPUTER APPLICATIONS IN FORESTRY AND TIMBER INDUSTRY; MODELLRECHNUNG UND COMPUTERANWENDUNGEN IN FORSTWIRTSCHAFT UND HOLZINDUSTRIE; NETZWERKPLANUNG (OPERATIONS RESEARCH); LANDWIRTSCHAFTLICHE STRASSEN + GÜTERWEGNETZE (STRASSENBAU, KULTURTECHNIK); FARM ROADS + AGRICULTURAL ROADS (ROAD CONSTRUCTION, RURAL ENGINEERING); NETWORK PLANNING (OPERATIONS RESEARCH); COMPUTERANWENDUNGEN IM STRASSEN- UND EISENBAHNBAU; FORESTRY ROADS + FOREST TRAILS (ROAD CONSTRUCTION); COMPUTER APPLICATIONS IN ROAD CONSTRUCTION AND RAILWAY ENGINEERING; FORSTSTRASSEN + WALDWEGE (STRASSENBAU); GRAPHENMODELLE (GRAPHENTHEORIE); GRAPH MODELS (GRAPH THEORY)