Perhaps you should try some spelling variations:
than thong » than thuong, toan thong, tran thong
xanh khong » nganh khong, anh thong, benh khong
thuc xanh » thuc hanh, thuc thanh, thuc dan
khoa than » khoa luan, hoa thai, hoa tan
thu sach » tu sach, thuat sach, thuoc sach
sach tri » sach tai, sach tren, sach truc
tri thuc » tri tue
khong he » khong khi, hong ha, khong _
sach dai » sach dao, sach bai, sach dat
dai thuc » dan thuc, dai thu, dai thua
thuc cac » thuc cach, tuc cac, phuc cac
cac khoa » cac khoan, cac khoi, dac khoa
su sach » so sach, vu sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu sach tri thuc xanh khong he thong ) or ( su sach dai thuc cac khoa than thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach tri thuc xanh khong he thong ) OR ( su sach dai thuc cac khoa than thong )).
• Adding a wildcard symbol may retrieve word variants: (( thu sach tri thuc xanh khong he thong ) or ( su sach dai thuc cac khoa than thong ))*.