Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
hieu va » lieu va, hieu qua
luc van » luoc van, luu van, luc va
duc van » duc va, duc tan, duc manh
cuu tre » cua tre, cau tren, cau treo
ha hoi » hoa hoi, ha noi, xa hoi
va cam » va cham, va cac, va cao

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 ky lang ha hoi. hieu va cam ((luc van) or (duc van)) hanh vi ((cuu tre) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ha hoi. hieu va cam ((luc van) OR (duc van)) hanh vi ((cuu tre) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ha hoi. hieu va cam ((luc van) or (duc van)) hanh vi ((cuu tre) or (dau tren))*.