6.  Investment in joint ventures (cont’d) 7. Revenue 8.1  Depreciation and amortization, shipping and handling expenses China Yuchai International Limited | Annual Report 2013 82 Depreciation and amortization of property, plant and equipment, prepaid operating leases and investment property  are included in the following captions. The ability of certain joint ventures of the Group to transfer funds to the Group in the form of cash dividend or to repay  advances made by the Group is subject to the approval of the lenders and relevant authorities. As of December 31, 2013, the Groups’ share of joint ventures’ capital commitment that are approved but not contracted  for and joint ventures’ contingent liabilities were Rmb 321 (US$52) (2012: Rmb 2,004) and Rmb 12,843 (US$2,098)  (2012: Rmb 12,836) respectively. According to Qingdao Municipal Government’s regulation, all hotels in Qingdao,  the People’s Republic of China, are imposed for tourism development levy and hotel augmentation levy which are  equivalent to 1% of total revenue and 3% of room revenue respectively. According to releases made by the Qingdao  Local Taxation Bureau, the tourism development levy and the hotel augmentation levy were withdrawn effective from  January 1, 2009 and September 1, 2010 respectively. As at December 31, 2013, the estimated tourism development  levy and hotel augmentation levy payable by the Group’s joint venture in Qingdao were Rmb 3,748 (US$612) (2012:  Rmb 3,748) and Rmb 9,095 (US$1,486) (2012: Rmb 9,088) respectively. The joint venture, together with other hotel  owners in Qingdao is currently negotiating with the Qingdao Municipal Government to waive such levies. The joint  venture is of the view that the authority is unlikely to collect such levies. Hence, the above levies have not been  provided in the accounts of the joint venture. NOTES TO THE CONSOLIDATED FINANCIAL  STATEMENTS  (RMB AND US$ AMOUNTS EXPRESSED IN THOUSANDS, EXCEPT PER SHARE DATA)  31.12.2011 31.12.2012 31.12.2013 31.12.2013 Rmb’000 Rmb’000 Rmb’000 US$’000 Sale of goods 15,378,190 13,381,025 15,809,894 2,583,274 Rendering of services Consisting of: Revenue from hotel and restaurant operations 61,813 63,290 85,164 13,916 Revenue from sale of development properties 3,821 4,640 6,758 1,104 Rental income 604 534 539 88 66,238 68,464 92,461 15,108 Revenue 15,444,428 13,449,489 15,902,355 2,598,382 31.12.2011 31.12.2012 31.12.2013 31.12.2013 Rmb’000 Rmb’000 Rmb’000 US$’000 Cost of sales 234,486 254,454 281,718 46,032 Research and development expenses 24,202 27,774 32,757 5,352 Selling, general and administrative expenses 70,155 66,257 74,464 12,167 328,843 348,485 388,939 63,551