=> oecd.18.04.00

• AERIAL SURVEYS
• CADASTRAL SURVEYS
• CASE STUDIES
• CENSUSES
• DATA COLLECTING
• ENUMERATION
• FIELD ACTIVITY
• FIELD RESEARCH
• INTERVIEWS
• MAIL SURVEYS
• OBSERVATION
• PUBLIC OPINION POLLS
• QUESTIONNAIRES
• REMOTE SENSING
• SAMPLE SURVEYS
• SAMPLING
• SURVEY AREA
• SURVEYS