Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
trien hoat » tien hoa
kham thong » khap thong, khau thong, pham thuong
hoat hang » hoan hoang, hoat dong, hoa lang
hang khoa » dung khoa
khoa kham » kho khan, khoa than
pho thong » he thong
sach tri » sach tai, sach tren, sach truc
tri phan » tri nhan, tai phan, trinh phan
phan cac » nhan cach, phan dau, phan lap
cac khoa » cac khoan, cac khoi, dac khoa
khoa pho » khoa phu, khoa khoa, khoa phau
vu sach » vu bach, su sach, vu khach
te sach » toc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu sach trien hoat hang khoa kham thong ) or ( te sach tri phan cac khoa pho thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach trien hoat hang khoa kham thong ) OR ( te sach tri phan cac khoa pho thong )).
• Adding a wildcard symbol may retrieve word variants: (( vu sach trien hoat hang khoa kham thong ) or ( te sach tri phan cac khoa pho thong ))*.