Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
nang xa » nang x, lang xa, mang xa
hanh de » hanh ve, hanh kem
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
cam thu » nam thu, cac thu, ca thu
thu dan » thuc dan, thu dang, thu ban
va cam » va cham, va cac, va cao
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cam thu dan ((dang dieu) or (hanh de)) cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cam thu dan ((dang dieu) OR (hanh de)) cua cu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cam thu dan ((dang dieu) or (hanh de)) cua cu".
• Adding a wildcard symbol may retrieve word variants: doc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cam thu dan ((dang dieu) or (hanh de)) cua cu*.