Perhaps you should try some spelling variations:
van nham » van nam, van nhan, van tham
nham thu » nham thuc, nam thu, pham thu
hieu van » hieu va, thien van, lieu va
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, tu cach
cao hoi » cau hoi, co hoi, cao hoc
te sach » toc sach
thu va » thuc va, thue va, tu va
vai va » mai va, dai va, lai va
hai va » hai van, thai va, hoi 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 (te sach)) ky nang cao hoi. hieu van nham thu va danh ((vai va) or (hai va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang cao hoi. hieu van nham thu va danh ((vai va) OR (hai va)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky nang cao hoi. hieu van nham thu va danh ((vai va) or (hai va)) thiet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky nang cao hoi. hieu van nham thu va danh ((vai va) or (hai va)) thiet*.