Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
hanh tai » thanh tai, hang tai, han tai
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
cao hoi » cau hoi, co hoi, cao hoc
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
tai va » thai va, mai va, tri va
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: su sach ((y nang) OR (v nang)) cao hoi. hieu ve cam ((thuc va) or (tuc xa)) hanh tai va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (v nang)) cao hoi. hieu ve cam ((thuc va) OR (tuc xa)) hanh tai va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) OR (v nang)) cao hoi. hieu ve cam ((thuc va) or (tuc xa)) hanh tai va trien".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) OR (v nang)) cao hoi. hieu ve cam ((thuc va) or (tuc xa)) hanh tai va trien*.