Perhaps you should try some spelling variations:
khan thong » khap thong, khau thong, nhan thong
cach thai » cach thoi, sach tham, lich thai
pho thong » he thong
sach tri » sach tai, sach tren, sach truc
tri thuc » tri tue
thuc van » thuc vat, thuc dan, thuc va
van khoa » van hoa, von khoa, san khoa
khoa pho » khoa phu, khoa khoa, khoa phau
thai hoc » dai hoc, bai hoc, hoi hoc
kho khan » khoa kham, khoa than
su sach » so sach, vu sach
tu cach » tu cac
hoc vat » hoc va, hoc viet, thuc vat
vat kho » vat khoa, van kho, vat khi

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 tri thuc van khoa pho thong ) or ( tu cach thai hoc vat kho khan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach tri thuc van khoa pho thong ) OR ( tu cach thai hoc vat kho khan thong ))*.