Perhaps you should try some spelling variations:
kkhoa thang » khoa than
thuc bach » truc bach, thuoc sach, thuc hanh
thuc cach » thuoc sach, truoc cach, thuc hanh
cach phan » cach pha, mach phan, cac phan
sach dai » sach dao, sach dat, sach dau
dai thuc » dan thuc, dai thu, dai thua
ha kkhoa » da khoa, xa khoa, nha khoa
sach bai » sach dao, cac bai, sach xa
bai thuc » bai thuoc, bao thuc, loai thuc
phan hoi » phan phoi, phan thoi, phan hoa
hoi thon » hoi thong, hoa thon, hoi tho
tu sach » thu sach, su sach, te sach
bach ha » bac ha, bich ha, sach ha

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 dai thuc bach ha kkhoa thang ) or ( tu sach bai thuc cach phan hoi thon ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach dai thuc bach ha kkhoa thang ) OR ( tu sach bai thuc cach phan hoi thon )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach dai thuc bach ha kkhoa thang ) or ( tu sach bai thuc cach phan hoi thon ))*.