Recreation areas Planning 29 Recreation 18 Parks 15 Management 13 Outdoor recreation 11 Congresses 9 National parks and reserves 8 Open spaces 8 Recreational use 7 Land use 6 Recreation centers 6 Bibliography 5 Environmental aspects 5 City planning 4 Design and construction 4 Periodicals 4 Public use 4 Sports facilities 4 Tourism 4 Landscape architecture 3 Law and legislation 3 Playgrounds 3 Recreational facilities 3 Regional planning 3 Research 3 Economic aspects 2 Environmental policy 2 Leisure 2 Recreational surveys 2