Perhaps you should try some spelling variations:
lang phi » lang phu, lang chai, lang ha
ban lang » ban hang, ba lang, ban dang
cay phoi » cap phoi, cay cho, gap phoi
su sach » so sach
phi cua » phai cua, chi cua, khi cua
dua ban » dia ban, cua ban, qua ban
cam dua » ca dua, cay dua, chay dua
hieu ve » hieu va, hieu van
tay hoi » tay ho, tao hoi, tay thai
ky dang » ky nang, ky danh
vu sach » vu bach, vu khach
cua tre » cua te, cuu tre, cua triet
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 (vu sach)) ky dang ((cay phoi) OR (tay hoi)). hieu ve cam dua ban lang phi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky dang ((cay phoi) OR (tay hoi)). hieu ve cam dua ban lang phi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky dang ((cay phoi) OR (tay hoi)). hieu ve cam dua ban lang phi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky dang ((cay phoi) OR (tay hoi)). hieu ve cam dua ban lang phi cua tre*.