Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh thuc » trinh thuc, trang thuc, thanh thuy
pho thong » he thong
phu thong » phap thong, khau thong, phan thong
thuc dan » thuc hanh, hoc dan, thuc vat
dan khoa » dang khoa, da khoa, san khoa
khoa pho » khoa khoa, khoa phau, khoa hoc
khoa phu » khoa phau, khoa thu, hoa phu
bo sach » co sach, hoc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( bo sach tranh thuc dan khoa pho thong ) or ( bo sach tranh thuc dan khoa phu thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( bo sach tranh thuc dan khoa pho thong ) OR ( bo sach tranh thuc dan khoa phu thong )).
• Adding a wildcard symbol may retrieve word variants: (( bo sach tranh thuc dan khoa pho thong ) or ( bo sach tranh thuc dan khoa phu thong ))*.