Perhaps you should try some spelling variations:
thieu nang » thien nang, thieu khang, thieu quang
pham thuc » phap thuc, pham chuc, nham thuc
hieu van » thien van, lieu va
dinh vai » dinh van, dinh vi, dinh va
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
cu tren » tu tren, dua tren
vai cu » vai cua, van cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach thieu nang xa hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) pham thuc va dinh vai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thieu nang xa hoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) pham thuc va dinh vai cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thieu nang xa hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) pham thuc va dinh vai cu tren".
• Adding a wildcard symbol may retrieve word variants: tu sach thieu nang xa hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) pham thuc va dinh vai cu tren*.