Taqwaconsulting - 6:23 am on Jul 17, 2011 (gmt 0)
I would suggest click on Exact match to find the real keyword with its real stats. This should help you in your planning.
Broad match is not good for analysis.
Well, as to your keywords, i see different search results for all of them. I selected Exact match when doing so. Here is what i get:
travel to Vietnam=4400
travel in Vietnam=1000
Vietnam and travel=140
This is on google keyword tool. All the keywords are identified separately by google.
I wonder what you were analyzing on? Hope this helps.