Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
cau tren » cu tren, dau tren, cau treo
thuoc ma » hoc ma, duoc ma
sach ky » sac ky, sach y, sach kem
dan van » dang van, doan van, dao van
ca tren » cu tren, la tren, co tren
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
ma dan » mat dan, mua dan, ca dan
va nam » van nam, ha nam, va nay

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ky) OR (sach ty)) lang xa hoi. hieu va nam thuoc ma dan van ((cau tren) OR (ca tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((sach ky) or (sach ty)) lang xa hoi. hieu va nam thuoc ma dan van ((cau tren) OR (ca tren))~".
• Adding a wildcard symbol may retrieve word variants: doc ((sach ky) or (sach ty)) lang xa hoi. hieu va nam thuoc ma dan van ((cau tren) OR (ca tren))*.