You don't say which country you are a national of. As a Brit my own first stop would be the FCO travel website. Try your own country's equivalent Foreign Office website. The FCO travel website Cambodia shows:
http://www.fco.gov.uk/en/travelling-and ... a/cambodia
Get an up-to-date guide book for Cambodia and read that carefully.
The above are basic for any travel and you shouldn't travel without doing this most basic of homework.
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Pamela
http://www.tribaltextiles.infoon-line tribal textiles resource