Perhaps you should try some spelling variations:
nay thuoc » cay thuoc, nam thuoc, na thuoc
dau tieng » dau tien, cau tieng, day tieng
sach thu » sach thue, sach thieu, sach tham
thuoc va » thuc va, thuoc ma, thuong va
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va nay » va ngay, va cay
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi dau » vi dai, va dau, bi dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ty) OR (sach thu)) nang xa hoi. hieu va nay thuoc va dan vi dau tieng~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) OR (sach thu)) nang xa hoi. hieu va nay thuoc va dan vi dau tieng".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) OR (sach thu)) nang xa hoi. hieu va nay thuoc va dan vi dau tieng*.