Perhaps you should try some spelling variations:
cam quoc » cac quoc, cao quoc, nam quoc
nam duoc » nam thuoc, da duoc, dat duoc
hieu van » hieu va, thien van, lieu va
benh te » benh tre, benh ve, benh he
bo benh » so benh, o benh, ba benh
lang xa » lang ha, dang xay, lang van
sach o » sach lo, sac o, mach o
te cua » tue cua, le cua, de cua
cua te » cua tu

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: te ((sach o) OR (sach y)) lang xa hoi. hieu van ((cam quoc) OR (nam duoc)) bo benh te cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach o) OR (sach y)) lang xa hoi. hieu van ((cam quoc) or (nam duoc)) bo benh te cua te~".
• Adding a wildcard symbol may retrieve word variants: te ((sach o) OR (sach y)) lang xa hoi. hieu van ((cam quoc) or (nam duoc)) bo benh te cua te*.