Perhaps you should try some spelling variations:
sinh thai » dinh thi
sach tien » sach tren, sach thieu
tien khoi » tien khi, trien khai, tien khoan
khoi khoa » hoi khoa, khoa khoa, khoi khong
toc sach » hoc sach, doc sach, thuoc sach
lin thai » tinh thai, hinh thai, lich thai
khoa hoc » hoa hoc
tu sach » thu sach, su sach, te sach

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

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