Perhaps you should try some spelling variations:
nam buoc » nam duoc, nam quoc, nam thuoc
toc sach » hoc sach, doc sach, thuoc sach
cam quoc » cac quoc, cao quoc, nam quoc
benh de » benh ve, benh he, menh de
bo benh » so benh, o benh, ba benh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
de cua » le cua, te cua, dieu cua
o lang » hoa lang, hoi lang
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) OR (toc sach)) o lang xa hoi. hieu va ((cam quoc) OR (nam buoc)) bo benh de cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) o lang xa hoi. hieu va ((cam quoc) or (nam buoc)) bo benh de cua te~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) o lang xa hoi. hieu va ((cam quoc) or (nam buoc)) bo benh de cua te*.