Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cong tac » cong ty
van hanh » van thanh, ban hanh, van anh
va dinh » van dinh, va kinh, va tinh
ky cong » ke cong, ly cong, khu cong
tac hoi » tao hoi, tay hoi, tac hai
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
sach ky » sac ky, sach y, sach ty
va hanh » va thanh, va danh, ban hanh
va cam » va cham, va cac, va cao
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky cong tac hoi. hieu va cam xuc ((((va hanh) or (van hanh))) or (va dinh)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky cong tac hoi. hieu va cam xuc ((((va hanh) OR (van hanh))) OR (va dinh)) vai cua te.
• Adding a wildcard symbol may retrieve word variants: doc sach ky cong tac hoi. hieu va cam xuc ((((va hanh) or (van hanh))) or (va dinh)) vai cua te*.