Perhaps you should try some spelling variations:
phan thong » phan thuong, phan hong, phan tong
thong hoa » thong khoa, thong ha, thong hoc
nhan dan » phan dau, gian dan, nhan tai
van nhan » van phan, van thanh, danh nhan
hoc phan » hoc dan, hoc pho
hoi van » hoi va, hoi dan, hai van
mai hoi » mai khoi, dai hoi, lai hoi
hoa mai » hoa dai, hoa may, hoa moi
su sach » so sach, vu sach
cuu mot » cua mot, cuu mo, huu mot
dai tai » dai hai, dai thao
doi dap » hoi dap, doi dau, do dap
mot hoc » mon hoc, mo hoc, mot goc

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 ((doi dap) or (dai tai)), nghien cuu mot hoc phan thong hoa mai hoi van nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((doi dap) OR (dai tai)), nghien cuu mot hoc phan thong hoa mai hoi van nhan dan*.