Perhaps you should try some spelling variations:
kinh thai » sinh thai, tinh thai, hinh thai
thai khoa » tai khoa, nhi khoa, hoi khoa
xin thai » sinh thai, tinh thai, hinh thai
lin thai » sinh thai, tinh thai, hinh thai
khoa hoc » hoa hoc
su sach » so sach, vu sach
so vac » so van, so vat, so va

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so vac ((xin thai) OR (lin thai)) khoa hoc ) or ( su sach kinh thai khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so vac ((xin thai) OR (lin thai)) khoa hoc ) OR ( su sach kinh thai khoa hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so vac ((xin thai) OR (lin thai)) khoa hoc ) or ( su sach kinh thai khoa hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( so vac ((xin thai) OR (lin thai)) khoa hoc ) or ( su sach kinh thai khoa hoc ))*.