Perhaps you should try some spelling variations:
"te sach tranh tai" » "te canh tranh tai", "te sach tranh thai", "te sach trinh tai", "te sach thanh tai"
"toc sach doanh tai" » "toc sach danh tai", "toc san doanh tai", "toc hanh doanh tai", "hoc sach doanh tai", "doc sach doanh tai", "thuoc sach doanh tai"
"te cac doanh tri" » "te cac dan tri", "te cac dang tri", "te van doanh tri", "te cac doanh tren", "te cac dinh tri", "te cac doanh thu", "tu cac doanh tri", "ve cac doanh tri", "te cao doanh tri"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("te cac doanh tri") or ((("te sach tranh tai") or ("toc sach doanh tai"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("te cac doanh tri") OR ((("te sach tranh tai") OR ("toc sach doanh tai")))).
• Removing quotes may allow a broader search: (( te cac doanh tri ) or ((( te sach tranh tai ) or ( toc sach doanh tai )))).
• Adding a wildcard symbol may retrieve word variants: (("te cac doanh tri") or ((("te sach tranh tai") or ("toc sach doanh tai"))))*.