Perhaps you should try some spelling variations:
thuc thanh » thuoc thanh, thuc hanh, phuc thanh
long thuc » luong thuc, long thuoc, cong thuc
thanh hoa » thanh pho
vu khach » vu khanh, vu khac, vay khach
cuu long » cuu cong, cuu tong, cuu nang
phan van » pham van, thanh van, luan van
so sach » so sanh, bo sach, co sach
va phan » van phan, va phat, va phap
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu khach) or (so sach)) hoc tap, nghien cuu long thuc thanh hoa hoc xa hoi va phan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (so sach)) hoc tap, nghien cuu long thuc thanh hoa hoc xa hoi va phan van.
• Adding a wildcard symbol may retrieve word variants: ((vu khach) or (so sach)) hoc tap, nghien cuu long thuc thanh hoa hoc xa hoi va phan van*.