Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
nang doc » nang luc
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
tu sach » thu sach, su sach, te sach
nang co » nang cao, nang noi, nang hoc
ve cham » ve chat, vu cham, ve chim
luc va » duc va, tuc va, loc va
ve dau » va dau, ve du, ke 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 y ((nang co) or (nang doc)) hoc. hieu ((ve cham) or (va cham)) luc va hanh ve dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang co) OR (nang doc)) hoc. hieu ((ve cham) OR (va cham)) luc va hanh ve dau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang co) or (nang doc)) hoc. hieu ((ve cham) or (va cham)) luc va hanh ve dau tren*.