Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
dau tren » dau tien, dat tren, dau tieng
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hanh va » hanh vi
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ma hoi. hieu van pham duc va ((hanh va) or (hang va)) dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ma hoi. hieu van pham duc va ((hanh va) OR (hang va)) dau tren.
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoi. hieu van pham duc va ((hanh va) or (hang va)) dau tren*.