Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hanh vai » hanh vi, hanh va, hanh tai
cham luc » cham soc, nhan luc, cham cuu
hieu van » thien van, lieu va, hieu ve
dang xay » dang van, van xay
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
vai cau » va cau, van cau, vai cac
su sach » so sach, vu sach
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((dang xay) or (nang ma)) hoi. ((hieu van) or (hieu va)) cham luc va hanh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((dang xay) OR (nang ma)) hoi. ((hieu van) OR (hieu va)) cham luc va hanh vai cau tren.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((dang xay) or (nang ma)) hoi. ((hieu van) or (hieu va)) cham luc va hanh vai cau tren*.