Perhaps you should try some spelling variations:
sach thi » sach thu, sach thieu, sach tham
sach tai » sach bai, sach tham, sach dao
hoang xa » hoang ha, hoang va, hoang xuan
cam thuc » am thuc, nam thuc, cam thu
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
hieu ve » hieu va, hieu van
so viet » hoc viet
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: tu ((sach thi) OR (sach tai)) hoang xa hoi. hieu ve cam thuc van hanh dai so viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach thi) OR (sach tai)) hoang xa hoi. hieu ve cam thuc van hanh dai so viet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach thi) OR (sach tai)) hoang xa hoi. hieu ve cam thuc van hanh dai so viet*.