Perhaps you should try some spelling variations:
thuc cach » thuoc sach, truoc cach, thuc hanh
cach khoi » cach thoi, cac khoi, cac thoi
thuat van » thuat san, thuat va, thuat ban
mach khoa » bach khoa, anh khoa, may khoa
khoa kham » kho khan, khoa than
kham tong » khau tong, pham trong, khac trong
sach thu » sach thue, sach thieu, sach tham
thu thuc » thuc thuc, thu thuoc, thue thuc
khoi han » hoi han, khoi can, khoa than
van tren » van tien, quan tren, van trung
tren tim » trien tin, trinh tim, trong tim
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach thu thuc cach khoi han tong ) or ( thuat van tren tim mach khoa kham tong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach thu thuc cach khoi han tong ) OR ( thuat van tren tim mach khoa kham tong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach thu thuc cach khoi han tong ) or ( thuat van tren tim mach khoa kham tong ))*.