Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thu sach » tu sach, thuoc sach, thu hoach
hanh lai » hanh lam, hanh tai, thanh lap
lai cua » dai cua, hai cua, lai chau
truc va » thuc va, trung va
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
ma hoi » mai hoi, xa hoi, ma hoa

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 (thuat sach)) ky nang ma hoi. hieu va cau ((truc va) OR (thuc vat)) hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) ky nang ma hoi. hieu va cau ((truc va) OR (thuc vat)) hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuat sach)) ky nang ma hoi. hieu va cau ((truc va) OR (thuc vat)) hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuat sach)) ky nang ma hoi. hieu va cau ((truc va) OR (thuc vat)) hanh lai cua tre*.