| X-ray Optics by Arthur James Cochran Wilson - 1949 - 127 pages |
| X-ray optics by Arthur James Cochran Wilson - 1949 - 127 pages |
| X-ray Protection by National Committee on Radiation Protection and Measurements (U.S.) - 1949 |
| X-rays in Theory and Experiment by Arthur Holly Compton, Samuel King Allison - 1949 - 828 pages |
| X-rays in Theory and Experiment by Arthur Holly Compton, Samuel King Allison - 1949 - 828 pages |
| Xangô by São Paulo (Brazil). Discoteca Pública Municipal, Oneyda Alvarenga - 1949 - 149 pages |
| Xari by Myriam Francis - 1949 - 126 pages |
| Xaver Fuhr, neunundvierzig Bilder by Xaver Fuhr, Carl Linfert - 1949 - 21 pages |
| Xavier de Paiva by Raul Esteves dos Santos - 1949 - 50 pages |
| Xi Jin yan yi by Canglangjiuyin - 1949 - 155 pages |
| Xi xing za ji by Jin Ba - 1949 - 102 pages |
| Xian dai he bi xue by Hong Fan - 1949 - 132 pages |
| Xian xing shui wu fa ling hui ji by China - 1949 - 270 pages |
| Xian Zhongguo di liang zhong she hui by Dongbei jun zheng da xue. Zheng zhi bu - 1949 - 211 pages |
| Xiang gang xue sheng shou ce - 1949 - 192 pages |
| Xiang zu zhi lian he zheng fu ma ni qiao Jieke by Fu Hua - 1949 - 27 pages |
| Xiangtan Tan Bannong xian sheng shi ji by Zhaode Tan - 1949 |
| Xiao Jun si xiang pi pan by Zhiming Liu - 1949 - 152 pages |
| Xiao tuan yuan by Canyun Chen - 1949 - 82 pages |
| Xiao xue jiao yu di li lun yu shi jian - 1949 - 128 pages |
| Xie hou ji by Zengji Wang - 1949 - 182 pages |
| XIIth International Dairy Congress by International Dairy Federation - 1949 |
| XIIth International Dairy Congress - 1949 |
| XIIth International Dairy Congress - 1949 |
| XIIth International Dairy Congress - 1949 |
| XIIth International Dairy Congress by International Dairy Federation - 1949 |
| XIIth International Dairy Congress by International Dairy Federation - 1949 |
| XIIth International Dairy Congress by International Dairy Federation - 1949 |
| XIIth International Dairy Congress by International Dairy Federation - 1949 |
| XIIth International Dairy Congress - 1949 |
| XIIth International Dairy Congress: Final report - 1949 |
| Xin cai zheng xue da gang by Jiaju Qian - 1949 - 277 pages |
| Xin di ren min di wen yi by Yang Zhou - 1949 - 35 pages |
| Xin hua yue bao - 1949 |
| Xin hua yue bao - 1949 |
| Xin hua yue bao - 1949 |
| Xin hua yue bao. Xin-hua yuebao - 1949 |
| Xin hua yue bao. Xin-hua yuebao - 1949 |
| Xin Jianshe - 1949 |
| Xin Jianshe - 1949 |
| Xin jiao yu di fang xiang by Xian dai jiao yu she, Junmin Xie - 1949 - 70 pages |
| Xin meng by Dongxi Hao - 1949 |
| Xin min zhu zheng zhi du ben by Zhe Tong, Yun Xiao - 1949 - 66 pages |
| Xin min zhu zhu yi cheng shi zheng ce by Shaoqi Liu - 1949 - 198 pages |
| Xin min zhu zhu yi gong shang zheng ce by Zedong Mao - 1949 - 128 pages |
| Xin min zhu zhu yi jiao yu di chuang zao by Huanping Lin - 1949 - 94 pages |
| Xin min zhu zhu yi jing ji zheng ce di shang jue by Feng Qiu - 1949 - 86 pages |
| Xin min zhu zhu yi lun by 毛澤東 - 1949 - 49 pages |
| Xin ren sheng guan by Minghuang You - 1949 - 102 pages |
| Xin she hui di xin nü gong by Zhonghua Renmin Gongheguo quan guo fu nü lian he hui - 1949 - 51 pages |
| Xin she hui xue di ji ben wen ti by Zhiyuan Shen - 1949 - 73 pages |
| Xin Zhongguo di jing ji by Huaiyu (pseud.) - 1949 - 34 pages |
| Xin ZhongGuo ji zhe shou ce - 1949 - 204 pages |
| Xin Zhongguo mao yi jing ji zhi nan by Jing ji dao bao she - 1949 - 184 pages |
| Xiong mei kai huang by Dahua Wang - 1949 - 54 pages |
| XIVe [i. e. Quatorzième] quatuor à cordes by Darius Milhaud - 1949 |
| XV. yüzyıl Konya-Karaman şairlerinden Aynî by Edip Âli Bakı - 1949 - 89 pages |
| XV. yüzyıl Konya-Karaman şairlerinden Aynî by Edip Âli Bakı - 1949 - 89 pages |
| XVe [i.e. Quinzième] quatuor à cordes, pour deux violons, alto et violoncello by Darius Milhaud - 1949 |
| XVe quatuor à cordes - 1949 |
| XVIIe siècle - 1949 |
| XVIIe siècle - 1949 |
| XVIIe siècle - 1949 |
| XXV poems by Frederick Eckman - 1949 - 32 pages |
| Xántus by Henry Miller Madden - 1949 - 312 pages |
| Xántus by Henry Miller Madden - 1949 - 312 pages |
| Xántus, Hungarian naturalist in the pioneer West by Henry Miller Madden - 1949 - 312 pages |
| Xénophon Économique by Xénophon - 1949 - 119 pages |
| Xénophon Économique by Xénophon - 1949 - 119 pages |