Perhaps you should try some spelling variations:
phan thuc » nhan thuc, phap thuc, pham thuc
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
van phan » van phong, van thanh, luan phan
tu sach » su sach, te sach, tu cach
cao hoi » cau hoi, co hoi, cao hoc
vat ran » chat ran, van ranh
ran vai » ran dai, trang vai, tran van
vai va » mai va, dai va, hai va
thiet » thieu

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)) ky nang cao hoi. hieu van phan thuc vat ran vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang cao hoi. hieu van phan thuc vat ran vai va thiet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang cao hoi. hieu van phan thuc vat ran vai va thiet*.