Perhaps you should try some spelling variations:
hau treo » cau treo, cau theo, dau tren
hang hai » hoang hai, hang tai, thanh hai
hanh hai » thanh hai, nhanh hai, hanh tai
hieu van » hieu va, thien van, lieu va
duc ban » duc tan, duc van, dua ban
tu sach » thu sach, su sach, te sach
sach ly » sach y, sach lo, sach ty
van cam » van nam, van lam, van cau
ly nang » ky nang, ly hang, ly vang
cam duc » cam xuc, cao duc, pham duc
x hoi » o hoi, x ho, 5 hoi

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 ly nang ((x hoi) or (xa hoi)). hieu van cam duc ban ((hanh hai) OR (hang hai)) hau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly nang ((x hoi) OR (xa hoi)). hieu van cam duc ban ((hanh hai) OR (hang hai)) hau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly nang ((x hoi) or (xa hoi)). hieu van cam duc ban ((hanh hai) OR (hang hai)) hau treo".
• Adding a wildcard symbol may retrieve word variants: tu sach ly nang ((x hoi) or (xa hoi)). hieu van cam duc ban ((hanh hai) OR (hang hai)) hau treo*.