Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » thuat sach, thu hoach, khau sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
danh tai » doanh tai, dinh tai, hanh tai
tu sach » su sach, te sach, tu cach
ky sang » ky nang, ky dang, ky tang
sang xa » song xa, lang xa, sang ma
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
cuc tre » duc tre, cua tre, cuu tre

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) or (thuoc sach)))) ky sang xa hoi. hieu van nam thuc va danh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((thu sach) OR (thuoc sach)))) ky sang xa hoi. hieu van nam thuc va danh tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((thu sach) or (thuoc sach)))) ky sang xa hoi. hieu van nam thuc va danh tai cuc tre*.