Perhaps you should try some spelling variations:
thuat tac » thuat tach, thuat tao, thuat tai
thi nang » thi cong, ki nang, thi hanh
thuc van » thuc vat, thuc dan, thuc va
thi van » thi lan, thi hanh
vuc van » duc van, luc van, chuc van
xay hoi » xa hoi, tay hoi, cay phoi
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua
tac o » tac co, tac so, tay o
o van » vo van, so van, do van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuat tac o van xay hoi. ((thi van) or (thi nang)) nam ((vuc van) OR (thuc van)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat tac o van xay hoi. ((thi van) OR (thi nang)) nam ((vuc van) OR (thuc van)) hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat tac o van xay hoi. ((thi van) or (thi nang)) nam ((vuc van) OR (thuc van)) hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat tac o van xay hoi. ((thi van) or (thi nang)) nam ((vuc van) OR (thuc van)) hanh di cua tre*.