Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nha thuoc, cay thuoc
cau tren » cu tren, dau tren, ca tren
lang van » dang van, tang van, hoang van
cuu tre » cua tre, cau treo
doc sac » doc sach, dac sac, hoc sach
hieu va » lieu va, hieu qua
van hoc » van hoa
ky lang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sac ky lang van hoc. hieu va ((nam thuoc) or (nam thu)) va dan va ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sac ky lang van hoc. hieu va ((nam thuoc) OR (nam thu)) va dan va ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: doc sac ky lang van hoc. hieu va ((nam thuoc) or (nam thu)) va dan va ((cuu tre) or (cau tren))*.