Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
vat hanh » vat thanh, van hanh, va hanh
sach ty » sach y, sach tu, xach tay
may hoi » may thoi, tay hoi, mai hoi
ve cam » ve cham, ve cac, ve cai
va cam » va cham, va cac, va cao
vi hoa » voi hoa, vi hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) OR (sach thu)) mang may hoi. hieu ((ve cam) or (va cam)) thuc vat hanh vi hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) mang may hoi. hieu ((ve cam) OR (va cam)) thuc vat hanh vi hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach thu)) mang may hoi. hieu ((ve cam) or (va cam)) thuc vat hanh vi hoa viet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) OR (sach thu)) mang may hoi. hieu ((ve cam) or (va cam)) thuc vat hanh vi hoa viet*.