Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cam thuc » am thuc, nam thuc, cam thu
vat hanh » vat thanh, van hanh, va hanh
sach ly » sach y, sach lo, sach ty
hang ca » nang cao, hang tai, hang dau
hieu ve » hieu va, hieu van
hanh va » hanh vi
su hien » su kien, su tien, thu hien
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: hoc sach ly ((hang ca) or (hang va)) hoi. hieu ve cam thuc vat hanh va su hien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ly ((hang ca) OR (hang va)) hoi. hieu ve cam thuc vat hanh va su hien.
• Adding a wildcard symbol may retrieve word variants: hoc sach ly ((hang ca) or (hang va)) hoi. hieu ve cam thuc vat hanh va su hien*.