Perhaps you should try some spelling variations:
cau tren » dau tren, ca tren, cau treo
dang xay » dang van, van xay
va hanh » van hanh, va thanh, va danh
nam xuc » cam xuc, nam xua, nam thuc
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
sach ty » sach y, sach tu, sach thu
cu tren » tu tren, dua tren
va nam » van nam, ha nam, va nay
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc ((sach ky) or (sach ty)) dang xay hoi. hieu va nam xuc va hanh vi ((cau tren) OR (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ky) OR (sach ty)) dang xay hoi. hieu va nam xuc va hanh vi ((cau tren) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach ky) or (sach ty)) dang xay hoi. hieu va nam xuc va hanh vi ((cau tren) OR (cu tren))".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ky) or (sach ty)) dang xay hoi. hieu va nam xuc va hanh vi ((cau tren) OR (cu tren))*.