Perhaps you should try some spelling variations:
thien van » thi van
nuoc sach » nguoi sach, hoc sach, cuoc cach
thu sach » tu sach, thuat sach, thuoc sach
lam truc » lam truoc, nam truc, lam thuoc
hieu van » hieu va, lieu va, hieu ve
tinh ve » trinh ve, tinh ven, dinh ve
va tinh » may tinh
truc va » thuc va, thuc vat, trung va
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (nuoc sach)) ky tang xa hoi. ((hieu van) or (thien van)) lam truc va tinh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (nuoc sach)) ky tang xa hoi. ((hieu van) OR (thien van)) lam truc va tinh ve cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (nuoc sach)) ky tang xa hoi. ((hieu van) or (thien van)) lam truc va tinh ve cua tre*.