Perhaps you should try some spelling variations:
ngang duoc » nganh duoc
nhan duoc » nhan cuoc, nhan quoc, phan duoc
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nam luc » nang luc, nhan luc, nam thuc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
luc va » duc va, tuc va, loc va
va cau » van cau, va cac, va dau

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 ty ((ngang duoc) or (nhan duoc)) hoi. hieu van nam luc va hanh va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((ngang duoc) OR (nhan duoc)) hoi. hieu van nam luc va hanh va cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((ngang duoc) or (nhan duoc)) hoi. hieu van nam luc va hanh va cau tren*.