id	keyword
ertr-84	park
ertr-84	constraint
ertr-84	et al
ertr-84	management
ertr-84	research
ertr-84	visit
ertr-84	constraint management
ertr-84	leisure
ertr-84	park visit
ertr-84	motivations
ertr-84	kim
ertr-84	tourism
ertr-84	visitation