LIANXIN, L. (1993). Self-locking theft-proof manhole cover (5.).
Chicago Style (17th ed.) CitationLIANXIN, LU. Self-locking Theft-proof Manhole Cover. 5. 1993.
MLA (9th ed.) CitationLIANXIN, LU. Self-locking Theft-proof Manhole Cover. 5. 1993.
Warning: These citations may not always be 100% accurate.