Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thu sach » tu sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
van tan » van tuan, van ban, van tai
dat ban » da ban, day ban, nhat ban
bat ban » bat can, bat bao, byt ban
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thuat sach)) ky nang ma hoi. hieu van tan ((dat ban) OR (bat ban)) hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) ky nang ma hoi. hieu van tan ((dat ban) OR (bat ban)) hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuat sach)) ky nang ma hoi. hieu van tan ((dat ban) OR (bat ban)) hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuat sach)) ky nang ma hoi. hieu van tan ((dat ban) OR (bat ban)) hanh vi cua vat*.