Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
van cam » van nam, van lam, van cau
vat han » vat phan, van han, vat ran
han tai » hang tai, nhan tai, van tai
cuc te » cua te, cuc thue, cuc tieu
x hoi » xa hoi, o hoi, x ho

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 (((hoc sach) or (hoc sinh)))) ky nang x hoi. hieu van cam thuc vat han tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (((hoc sach) OR (hoc sinh)))) ky nang x hoi. hieu van cam thuc vat han tai cuc te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (((hoc sach) or (hoc sinh)))) ky nang x hoi. hieu van cam thuc vat han tai cuc te*.