Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh lai » hanh lam, hanh tai, thanh lap
may khoa » da khoa, ly khoa, y khoa
sach ky » sac ky, sach y, sach ty
lai cua » dai cua, hai cua, lai chau
ve cham » va cham, ve chat, vu cham
may hoa » ma hoa, day hoa, mai hoa
hieu ve » hieu va, hieu van
ky mang » ky nang, ke mang, ky dang
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va

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 ky mang ((may hoa) OR (may khoa)). hieu ve cham ((xuc va) or (thuc vat)) hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky mang ((may hoa) OR (may khoa)). hieu ve cham ((xuc va) OR (thuc vat)) hanh lai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky mang ((may hoa) OR (may khoa)). hieu ve cham ((xuc va) or (thuc vat)) hanh lai cua tre*".