Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
su sach » so sach, vu sach
truc va » thuc va, thuc vat, trung va
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
va cua » va chua, via cua, ca cua
xuc va » duc va, tuc va, luc va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang xa hoi. ((hieu van) OR (hieu va)) nam ((xuc va) or (truc va)) hang va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. ((hieu van) OR (hieu va)) nam ((xuc va) OR (truc va)) hang va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang xa hoi. ((hieu van) OR (hieu va)) nam ((xuc va) or (truc va)) hang va cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. ((hieu van) OR (hieu va)) nam ((xuc va) or (truc va)) hang va cua te*.