Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
tuan van » luan van, tran van, tan van
cong doi » vong doi, cong dot, cong goi
thai anh » thai danh, thi anh, hai anh
vat thai » van thai, vat tai, chat thai
hoat hoc » hoa hoc, hoat ho, khoa hoc
dan hoat » van hoa, dan hoc, danh hoa
cac cong » cua cong
sach moi » sach hoi, bach mai, sach bai
sach doi » sach hoi, sach dao, sach bai
doi dan » hoi dan, doi ban, doi dau
hoc vat » hoc va, hoc viet, thuc vat

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach moi) OR (sach doi)) tap, nghien cac cong doi dan hoat hoc vat thai anh tuan van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach moi) OR (sach doi)) tap, nghien cac cong doi dan hoat hoc vat thai anh tuan van".
• Adding a wildcard symbol may retrieve word variants: su ((sach moi) OR (sach doi)) tap, nghien cac cong doi dan hoat hoc vat thai anh tuan van*.