Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cam thuc » am thuc, nam thuc, cam thu
su tien » su kien, tu tieng, dau tien
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
su hien » su kien, thu hien, nhu hien
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam

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 ly ((nang cao) or (hang va)) hoi. hieu ve cam thuc va danh va ((su tien) or (su hien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ly ((nang cao) OR (hang va)) hoi. hieu ve cam thuc va danh va ((su tien) OR (su hien)).
• Adding a wildcard symbol may retrieve word variants: thu sach ly ((nang cao) or (hang va)) hoi. hieu ve cam thuc va danh va ((su tien) or (su hien))*.