Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
phuc va » phuc vu, chuc va, thuc vat
van cau » van dau, van hau, van chat
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
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: thuoc sach y nang ma hoi. hieu van cau ((phuc va) OR (thuc va)) hanh tai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y nang ma hoi. hieu van cau ((phuc va) OR (thuc va)) hanh tai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y nang ma hoi. hieu van cau ((phuc va) OR (thuc va)) hanh tai ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y nang ma hoi. hieu van cau ((phuc va) OR (thuc va)) hanh tai ((cua tre) or (cuu tre))*.