Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
toc sach » hoc sach, doc sach, nuoc sach
nam thuc » nam thuoc, am thuc, nam thu
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
hieu va » lieu va, hieu qua
vat han » vat phan, van han, vat ran
han tai » hang tai, nhan tai, van tai
buu tre » cuu tre
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (thuoc sach)) ((ky lang) OR (ky tang)) xa hoi. hieu va nam thuc vat han tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuoc sach)) ((ky lang) OR (ky tang)) xa hoi. hieu va nam thuc vat han tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (thuoc sach)) ((ky lang) OR (ky tang)) xa hoi. hieu va nam thuc vat han tai buu tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thuoc sach)) ((ky lang) OR (ky tang)) xa hoi. hieu va nam thuc vat han tai buu tre*.