Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang doc » nang luc
dau tren » dau tien, dat tren, dau tieng
va cham » va chat, va tham
nang co » nang cao, nang noi, nang hoc
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
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: thu 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: thu sach y ((nang co) OR (nang doc)) hoc. hieu ((ve cham) OR (va cham)) luc va hanh ve dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu 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: thu sach y ((nang co) OR (nang doc)) hoc. hieu ((ve cham) or (va cham)) luc va hanh ve dau tren*.