Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
vat xanh » vat thanh, sat anh, dat anh
xanh di » danh di, vanh dai, xanh tai
van hac » van hoc, van ha, van hai
van bac » van ban, van bao, dan bac
tu sach » su sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ty nang ma hoi. hieu ((van bac) or (van hac)) thuc vat xanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty nang ma hoi. hieu ((van bac) OR (van hac)) thuc vat xanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty nang ma hoi. hieu ((van bac) or (van hac)) thuc vat xanh di cua tre*.