Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
trinh via » trinh va, trinh vi, trinh dia
van trinh » van thinh, van tinh, dan trinh
tu sach » thu sach, su sach, te sach
via cua » gia cua, gian cua, giau cua
xuc van » duc van, luc van, vuc van
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, kho tang
ve cac » va cac, vien cac
ma hoi » mai hoi, ma hoa, me 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) or (thuoc sach)) ky tang ((ma hoi) OR (xa hoi)). hieu ve cac xuc van trinh via cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky tang ((ma hoi) OR (xa hoi)). hieu ve cac xuc van trinh via cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ky tang ((ma hoi) OR (xa hoi)). hieu ve cac xuc van trinh via cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky tang ((ma hoi) OR (xa hoi)). hieu ve cac xuc van trinh via cua tre*.