Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
sach thu » sach thue, sach thieu, sach tham
sach ty » sach y, sach tu, xach tay
va hanh » van hanh, va thanh, va danh
cac xuc » cam xuc, cac nuoc, chat xuc
qua cac » cua cac
nang ma » tang ma, sang ma, nang cao
mang xa » lang xa, mang may, dang xay
xuc va » duc va, tuc va, luc va
vi va » vi van, vai va, vu va

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) or (sach thu)) ((mang xa) or (nang ma)) hoi. hieu qua cac xuc va hanh vi va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) ((mang xa) OR (nang ma)) hoi. hieu qua cac xuc va hanh vi va trien.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) ((mang xa) or (nang ma)) hoi. hieu qua cac xuc va hanh vi va trien*.