Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
hieu ve » hieu va, hieu van
dan dan » dang dan, ban dan, dao dan
cuu tre » cua tre, cau tren, cau treo
vu sac » vu sach, vu san, vu cac
va sac » va cac, va suc, va san
ve nam » he nam, va nam, le nam
dan di » danh di, dan da, dan de
di cuu » di cau, di cua, dinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sac) OR (va sac)) ky nang ((x ho) or (xa hoi)). hieu ve nam thuc dan dan di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sac) OR (va sac)) ky nang ((x ho) OR (xa hoi)). hieu ve nam thuc dan dan di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sac) OR (va sac)) ky nang ((x ho) or (xa hoi)). hieu ve nam thuc dan dan di cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sac) OR (va sac)) ky nang ((x ho) or (xa hoi)). hieu ve nam thuc dan dan di cuu tre*.