Perhaps you should try some spelling variations:
tieng thai » tieng han, tieng nhat, tinh thai
mach khien » mach dien, cach thien
tien chai » tien khi, trien chi, tien mai
khien cho » khien hoc, hiem cho, dien cho
thu sach » tu sach, thuat sach, thuoc sach
khoa hoc » hoa hoc
cho khoa » chi khoa, che khoa, cao khoa
tu mach » tu cach, tu manh, tu hach

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 ((tien chai) OR (tieng thai)) khoa hoc ) or ( tu mach khien cho khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach ((tien chai) OR (tieng thai)) khoa hoc ) OR ( tu mach khien cho khoa hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thu sach ((tien chai) OR (tieng thai)) khoa hoc ) or ( tu mach khien cho khoa hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( thu sach ((tien chai) OR (tieng thai)) khoa hoc ) or ( tu mach khien cho khoa hoc ))*.