Perhaps you should try some spelling variations:
van viet » san viet, gian viet, tran viet
tu sach » thu sach, su sach, te sach
ly vang » ly hang, ly van, ly quang
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va cam » va cham, va cac, va cao
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va

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 vang) or (ky nang)) cau hoi. hieu va cam duc va dan vi van viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ly vang) OR (ky nang)) cau hoi. hieu va cam duc va dan vi van viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ly vang) or (ky nang)) cau hoi. hieu va cam duc va dan vi van viet*.