Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa
tang mai » tang ma, tang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
su sach » so sach, vu sach
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va, hieu van
ky tang » ky nang, ky dang, kho tang
su cac » tu cac, su cao, su can
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) or (su cac)) ky tang mai khoi. hieu ve cam duc ban ((thanh hai) or (thanh san)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (su cac)) ky tang mai khoi. hieu ve cam duc ban ((thanh hai) OR (thanh san)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (su cac)) ky tang mai khoi. hieu ve cam duc ban ((thanh hai) or (thanh san)) cua tre*.