Perhaps you should try some spelling variations:
nham khoan » nham hoan, pham khoa, nha khoa
khoan phai » khong phai, khoa phau, khoan hoi
dung hoai » dung hai, dang hoai, dung hoa
cac nham » cac nha, cac nhan, cac ham
toc sach » hoc sach, doc sach, thuoc sach
hoai khi » doi khi, hoai thu, hoai bui

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu cac nham khoan phai đong luc ) or ( toc sach dung hoai khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu cac nham khoan phai đong luc ) OR ( toc sach dung hoai khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( tu cac nham khoan phai đong luc ) or ( toc sach dung hoai khi đong luc ))*.