Perhaps you should try some spelling variations:
cau treo » cau theo, cau tren, cau triet
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cuu tre » cua tre, cau tren
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, ve cai
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. hieu ((ve cam) or (va cam)) luc van hanh tai ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu ((ve cam) OR (va cam)) luc van hanh tai ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. hieu ((ve cam) or (va cam)) luc van hanh tai ((cuu tre) OR (cau treo))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu ((ve cam) or (va cam)) luc van hanh tai ((cuu tre) OR (cau treo))*.