Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh tai » thanh toan, doanh tai, thanh san
cam cac » ca cac, nam cac, cam chan
duc tre » duoc tren, duc tien
sach ky » sac ky, sach ty, sach kem
hieu ve » hieu va, hieu van
cao hoc » co hoc, cho hoc, chat hoc
ve cam » ve cham, ve cac, va cam

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 ky) or (sach y)) nang cao hoc. hieu ve cam cac dan ((thanh tai) OR (thanh hai)) duc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang cao hoc. hieu ve cam cac dan ((thanh tai) OR (thanh hai)) duc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach y)) nang cao hoc. hieu ve cam cac dan ((thanh tai) OR (thanh hai)) duc tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang cao hoc. hieu ve cam cac dan ((thanh tai) OR (thanh hai)) duc tre*.