Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cau treo » cau theo, cau triet, cau trieu
hanh hai » thanh hai, nhanh hai, hang hai
van hanh » van thanh, ban hanh, van anh
tuc van » thuc van, truc van, tuc va
cam tuc » cam xuc, cam tu, nam thuc
su sach » so sach, vu sach
ly hang » ly quang
ly nang » ky nang, ly vang, ly quang
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao

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 ((ly nang) or (ly hang)) ma hoi. lieu va cam tuc van hanh hai ((cau treo) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly nang) OR (ly hang)) ma hoi. lieu va cam tuc van hanh hai ((cau treo) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ly nang) or (ly hang)) ma hoi. lieu va cam tuc van hanh hai ((cau treo) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ly nang) or (ly hang)) ma hoi. lieu va cam tuc van hanh hai ((cau treo) OR (cau tren))*.