Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang xa hoi. hieu va cao ((truc va) or (thuc dan)) danh ((hoi cua) OR (hoi chuc)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. hieu va cao ((truc va) OR (thuc dan)) danh ((hoi cua) OR (hoi chuc)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. hieu va cao ((truc va) or (thuc dan)) danh ((hoi cua) OR (hoi chuc)) tu".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. hieu va cao ((truc va) or (thuc dan)) danh ((hoi cua) OR (hoi chuc)) tu*.