Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
truc va » thuc va, trung va
su sach » so sach
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
vu sach » vu bach, vu khach
ma hoi » mai hoi, xa hoi, ma hoa
va cua » va chua, via cua, ca cua
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ty nang ma hoi. hieu van nam ((truc va) OR (thuc vat)) hanh va cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ty nang ma hoi. hieu van nam ((truc va) or (thuc vat)) hanh va cua te~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ty nang ma hoi. hieu van nam ((truc va) or (thuc vat)) hanh va cua te*.