Perhaps you should try some spelling variations:
sach truc » cach thuc, sach tren, sach thu
truc nang » truc nano, tru nang, truc trang
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
tham xuc » tham nuoc, tham thuc, pham duc
tu sach » thu sach, su sach, te sach
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
su viet » so viet
ma hoi » mai hoi, xa hoi, me hoi
ki su » ky su

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 truc nang ((ma hoi) or (ma hoa)). hieu va tham xuc ((van hanh) OR (van thanh)) ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach truc nang ((ma hoi) OR (ma hoa)). hieu va tham xuc ((van hanh) OR (van thanh)) ki su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach truc nang ((ma hoi) or (ma hoa)). hieu va tham xuc ((van hanh) OR (van thanh)) ki su viet*".