Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dinh cuu » dinh chi
hieu van » thien van, lieu va, hieu ve
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau
di cuu » di cau, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky tang xa hoi. ((hieu va) or (hieu van)) cam xuc va dan ((di cuu) or (dinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky tang xa hoi. ((hieu va) OR (hieu van)) cam xuc va dan ((di cuu) OR (dinh cuu)) tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ky tang xa hoi. ((hieu va) or (hieu van)) cam xuc va dan ((di cuu) or (dinh cuu)) tre*.