Perhaps you should try some spelling variations:
tru nang » tra nang, tri nang, truc nano
tu sach » thu sach, su sach, te sach
ve chat » va chat, van chat
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
tu nang » tu nong, tu nano, tu lang
va cua » va chua, via cua, ca cua
ve cai » va cai, ve cac, ve tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((tu nang) OR (tru nang)) cau hoi. hieu ((ve cai) or (ve chat)) ly va danh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tu nang) OR (tru nang)) cau hoi. hieu ((ve cai) OR (ve chat)) ly va danh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tu nang) OR (tru nang)) cau hoi. hieu ((ve cai) or (ve chat)) ly va danh va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tu nang) OR (tru nang)) cau hoi. hieu ((ve cai) or (ve chat)) ly va danh va cua tre*.