Perhaps you should try some spelling variations:
kham thong » khap thong, khau thong, pham thuong
khoa kham » kho khan, khoa than
canh khoa » anh khoa, xanh khoa, doanh khoa
khoan pho » khoan nhoi, khoan phai, khoan hoi
pho thong » he thong
sach doi » sach hoi, sach moi, sach dao
su sach » so sach, vu sach
tu sach » thu sach, te sach, tu cach
tri ve » tri le, trinh ve
te cac » tu cac, ve cac, te cao
doi te » doi tw, doi de, toi te

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach doi te cac khoan pho thong ) or ( tu sach ((tri ve) OR (tri va)) canh khoa kham thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach doi te cac khoan pho thong ) OR ( tu sach ((tri ve) OR (tri va)) canh khoa kham thong )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( su sach doi te cac khoan pho thong ) or ( tu sach ((tri ve) OR (tri va)) canh khoa kham thong ))".
• Adding a wildcard symbol may retrieve word variants: (( su sach doi te cac khoan pho thong ) or ( tu sach ((tri ve) OR (tri va)) canh khoa kham thong ))*.