Perhaps you should try some spelling variations:
thuyet trinh » thuyet kinh
truc thuyet » truc tuyen, suc thuyet, truc thuy
khuan khoi » khuan khoa, khuan noi, hun khoi
trinh khoa » trinh hoa, sinh khoa, trinh hoi
thuoc sac » thuoc sach, thuoc dac, thuoc sai
thai thuc » thai thuy, thai tuc, tham thuc
anh khuan » anh chuan, anh tuan, anh khoa
sach truc » cach thuc, sach tren, sach thu
pho thong » he thong
sac thai » rac thai, sach tham, toc thai
thuc anh » thuc hanh, thuy anh, thu anh
khoa pho » khoa phu, khoa khoa, khoa phau
su sach » so sach, vu sach
khong » phong

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thuoc sac thai thuc anh khuan khoi khong ) or ( su sach truc thuyet trinh khoa pho thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuoc sac thai thuc anh khuan khoi khong ) OR ( su sach truc thuyet trinh khoa pho thong )).
• Adding a wildcard symbol may retrieve word variants: (( thuoc sac thai thuc anh khuan khoi khong ) or ( su sach truc thuyet trinh khoa pho thong ))*.