Perhaps you should try some spelling variations:
may thoi » gay thoi, may thi, tay thoi
su sach » so sach, vu sach
ky mang » ky nang, ky dang, ky tang
ke mang » ke nang, ke trang
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
tuc va » thuc va, truc va, tuc xa
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 ((ky mang) or (ke mang)) may thoi. hieu ve cam ((tuc va) or (thuc vat)) hanh vi hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky mang) OR (ke mang)) may thoi. hieu ve cam ((tuc va) OR (thuc vat)) hanh vi hoa viet.
• Adding a wildcard symbol may retrieve word variants: su sach ((ky mang) or (ke mang)) may thoi. hieu ve cam ((tuc va) or (thuc vat)) hanh vi hoa viet*.