Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua

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 (su sach)) ky nang ma hoa. hieu ((van ban) or (van hanh)) truc va danh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ma hoa. hieu ((van ban) OR (van hanh)) truc va danh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang ma hoa. hieu ((van ban) or (van hanh)) truc va danh de cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang ma hoa. hieu ((van ban) or (van hanh)) truc va danh de cua tre*.