Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
nghien huu » nghien cuu, nguyen huu, nhiem huu
pho thong » he thong
sach hoc » cach hoc, sach hoi, mach hoc
tung hoc » trung hoc, tuong hoc, dung hoc
pho hong » pho uong, pho dong, pho cong
phat van » pham van, phan van, phap van
doc xa » duoc xa, hoc xa, do xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach hoc tap, nghien huu tung hoc ((pho hong) OR (pho thong)) doc xa hoi va phat van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach hoc tap, nghien huu tung hoc ((pho hong) OR (pho thong)) doc xa hoi va phat van".
• Adding a wildcard symbol may retrieve word variants: thuat sach hoc tap, nghien huu tung hoc ((pho hong) OR (pho thong)) doc xa hoi va phat van*.