Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
dua tren » dung tren
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
va cam » va cham, va cac, va cao
vi dua » vi du, vi dum, vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ty ((nang x) or (nang ma)) hoi. hieu va cam duc va danh vi dua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty ((nang x) OR (nang ma)) hoi. hieu va cam duc va danh vi dua tren*.