Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
van thanh » ban thanh, van tuan
thanh tai » thanh hai, thanh toan, doanh tai
toc sach » hoc sach, doc sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
cua dang » cua cong, cua ban
dang hoa » dang hoai, dang khoa, dong hoa
dan hoat » van hoa, dan hoc, danh hoa
hoat hoc » hoa hoc, hoat ho, khoa hoc
xa thai » ca thai, a thai, da thai
xa hai » xua hai, xa hoi, xa dai

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 hoc tap, nghien cua dang hoa dan hoat hoc ((xa hai) OR (xa thai)) van thanh tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach hoc tap, nghien cua dang hoa dan hoat hoc ((xa hai) OR (xa thai)) van thanh tai".
• Adding a wildcard symbol may retrieve word variants: toc sach hoc tap, nghien cua dang hoa dan hoat hoc ((xa hai) OR (xa thai)) van thanh tai*.