Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
hieu va » lieu va, hieu qua
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
tang ma » mang may, tang van
xuc va » duc va, tuc va, luc va
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: ((te sach) or (toc sach)) ky ((nang x) or (tang ma)) hoi. hieu va cam xuc va hanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky ((nang x) OR (tang ma)) hoi. hieu va cam xuc va hanh tai cua te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky ((nang x) or (tang ma)) hoi. hieu va cam xuc va hanh tai cua te*.