Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh vai » tinh va, tinh hai, tinh bai
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
va tinh » may tinh
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
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)) ty ((nang xa) or (nang ma)) hoi. hieu van cac duc va tinh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty ((nang xa) OR (nang ma)) hoi. hieu van cac duc va tinh vai cua te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty ((nang xa) or (nang ma)) hoi. hieu van cac duc va tinh vai cua te*.