Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
cua tre » cuu tre, cua triet, dua tren
tuc va » thuc va, truc va, tuc xa
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: vu sach ty nang xa hoi. hieu van cac ((duc va) or (tuc va)) hanh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang xa hoi. hieu van cac ((duc va) OR (tuc va)) hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang xa hoi. hieu van cac ((duc va) or (tuc va)) hanh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang xa hoi. hieu van cac ((duc va) or (tuc va)) hanh vi ((cua tre) OR (cua te))*.